The Child Health and Development Studies is a ≥40-year follow-up of 20,754 pregnancies occurring between 1959 and 1967 in California. There were 84 cases of undescended testes at birth persisting to at least age 2 years among 7,574 liveborn sons whose mothers were interviewed in early pregnancy. Cases were matched to three controls on birth year and race. Compared with mothers of controls, mothers of cryptorchid boys consumed more caffeine during pregnancy (odds ratio = 1.4, 95% confidence interval: 1.1, 1.9 for an interquartile range equivalent to three cups of coffee per day) but were not more likely to smoke or drink alcohol when all behaviors were considered together. Other maternal and perinatal risk factors were not significantly associated with persistent cryptorchidism and did not confound the association with caffeine.
alcohol drinking; caffeine; cryptorchidism; pregnancy; prospective studies; risk factors; smoking
Ages at menarche and first birth are established risk factors for breast cancer. The interval between these ages may also affect risk, since the breast is more susceptible to carcinogenic insults during this period than during the parous period. However, few investigators have studied this relation. Using logistic regression, the authors evaluated associations between the timing of reproductive events and breast cancer risk among 4,013 cases and 4,069 controls enrolled in a multicenter, population-based US case-control study of White and African-American women (1994–1998). For White, parous premenopausal and postmenopausal women, those who had an interval of ≥16 years between the ages of menarche and first birth had 1.5-fold (95% confidence interval (CI): 1.0, 2.2) and 1.4-fold (95% CI: 1.1, 1.8) increased risks of breast cancer, respectively, in comparison with those who had ≤5 years between these ages. Adjusting for age at first birth altered these risk estimates somewhat, to odds ratios of 1.5 (95% CI: 0.8, 2.9) and 1.0 (95% CI: 0.6, 1.5), respectively. These associations were stronger for lobular and hormone-receptor-positive tumors but were absent among premenopausal African-American women. The authors conclude that the interval between age at menarche and age at first birth is associated with the risk of hormonally sensitive types of breast cancer, particularly among White women.
breast neoplasms; histology; menarche; menopause; pregnancy; premenopause; receptors, estrogen; receptors, progesterone
Most surveys of the prevalence of psychiatric disorders among lesbians and gay men find no increased risk in comparison with heterosexuals. However, the majority of this work has relied on convenience samples drawn from the visible lesbian and gay community. The authors examined differences in 1-year prevalence of six psychiatric syndromes among sexually active individuals in the 1996 National Household Survey of Drug Abuse who reported either exclusive heterosexuality (n = 9,714) or having any same-gender sex partners (n = 194) in the prior year. Although nearly three quarters of homosexually active individuals did not meet criteria for any of the six syndromes assessed, in multivariate logistic regression analyses, homosexually active men were more likely than other men to evidence major depression and panic attack syndromes. In contrast, homosexually active women were more likely than other women to be classified with alcohol or drug dependency syndromes. Both men and women reporting any same-gender sex partners were more likely than others to have used mental health services in the year prior to interview. These findings suggest a small increased risk among homosexually active populations in 1-year psychiatric morbidity and use of mental health care services.
health surveys; homosexuality; mental disorders; psychiatry; substance-related disorders
Physical activity tends to decline from childhood into adulthood. The maintenance of high levels of physical activity throughout life is therefore an important public health objective. Relatively little is known about changes in physical activity behavior over the life course, the domains of physical activity in which they occur, the characteristics of those whose physical activity declines and the factors associated with such changes. In future, the incorporation of more accurate measures of physical activity in large population studies would help to establish more accurate estimates of associations in this area. Determinants of behavior change, including the effects of socioeconomic position and social mobility on physical activity and fitness, are likely to change constantly throughout life, but it is largely unknown which determinants are most important at each life stage, let alone whether and at what times those determinants change. Better evidence on determinants of behavior change throughout the life course would contribute greatly to our understanding of when and how to intervene in order to help create and sustain lifelong healthy behavior patterns in those who have most to gain from adopting them.
Physical activity; determinants; behavior change; transition
Explanations for the low prevalence of atherosclerosis in Japan versus United States are often confounded with genetic variation. To help remove such confounding, coronary artery calcification (CAC), a marker of subclinical atherosclerosis, was compared between Japanese men in Japan and Japanese men in Hawaii. Findings are based on risk factor and CAC measurements that were made from 2001 to 2005 in 311 men in Japan and 300 men in Hawaii. Men were aged 40 to 50 years and without cardiovascular disease. After age-adjustment, there was a 3-fold excess in the odds of prevalent CAC scores ≥10 in Hawaii versus Japan (relative odds [RO] = 3.2; 95% confidence interval [CI] = 2.1,4.9). While men in Hawaii had a generally poorer risk factor profile, men in Japan were 4-times more likely to smoke cigarettes (49.5 vs. 12.7%, p<0.001). In spite of marked risk factor differences between the samples, none of the risk factors provided an explanation for the low amounts of CAC in Japan. After risk factor adjustment, the RO of CAC scores ≥10 in Hawaii versus Japan was 4.0 (95% CI = 2.2,7.4). Further studies are needed to identify factors that offer protection against atherosclerosis in Japanese men in Japan.
Atherosclerosis; cohort studies; coronary disease; Japan; men; risk factors
Coronary heart disease (CHD) incidence and mortality remain very low in Japan despite major dietary changes and increases in CHD risk factors that should have resulted in substantial increase in CHD rates (Japanese paradox). Primary genetic effects are unlikely, given the substantial increase in CHD in migrant Japanese to the U.S. For men aged 40–49, levels of total cholesterol and blood pressure have been similar in Japan and the U.S. throughout their lifetime. The authors tested the hypothesis that levels of subclinical atherosclerosis, coronary artery calcification and intima-media thickness of the carotid artery (IMT), in men aged 40–49 are similar in Japan and the U.S. The authors conducted a population-based study of 493 randomly-selected men: 250 men in Kusatsu, Shiga, Japan, and 243 white men in Allegheny County, Pennsylvania, U.S. in 2002–2005. The Japanese had a less favorable profile of many risk factors than the whites. Prevalence ratio for the presence of coronary calcium score ≥10 in the Japanese compared to the whites was 0.52 (95% CI, 0.35, 0.76). Mean (SE) IMT was significantly lower in the Japanese (0.616 (0.005) versus 0.672 (0.005) mm, p<0.01). Both associations remained significant after adjusting for risk factors. The findings warrant further investigations.
Atherosclerosis; epidemiology; men; risk factors
Leukocyte telomere length, representing the mean length of all telomeres in leukocytes, is ostensibly a bioindicator of human aging. The authors hypothesized that shorter telomeres might forecast imminent mortality in elderly people better than leukocyte telomere length. They performed mortality analysis in 548 same-sex Danish twins (274 pairs) aged 73–94 years, of whom 204 pairs experienced the death of one or both co-twins during 9–10 years of follow-up (1997–2007). From the terminal restriction fragment length (TRFL) distribution, the authors obtained the mean TRFL (mTRFL) and the mean values of the shorter 50% (mTRFL50) and shortest 25% (mTRFL25) of TRFLs in the distribution and computed the mode of TRFL (MTRFL). They analyzed the proportions of twin pairs in which the co-twin with the shorter telomeres died first. The proportions derived from the intrapair comparisons indicated that the shorter telomeres predicted the death of the first co-twin better than the mTRFL did (mTRFL: 0.56, 95% confidence interval (CI): 0.49, 0.63; mTRFL50: 0.59, 95% CI: 0.52, 0.66; mTRFL25: 0.59, 95% CI: 0.52, 0.66; MTRFL: 0.60, 95% CI: 0.53, 0.67). The telomere-mortality association was stronger in years 3–4 than in the rest of the follow-up period, and it grew stronger with increasing intrapair difference in all telomere parameters. Leukocyte telomere dynamics might help explain the boundaries of the human life span.
aged; leukocytes; mortality; survival analysis; telomere; twins
Because of the aging of the population, dementia has become a major public health problem. There has been growing evidence for a possible association between lipids and dementia. A large body of literature has demonstrated multiple hypothesized biologic links between lipids and neurodegenerative or other biologic pathways connected to dementing processes. However, the epidemiologic associations have been conflicting: dyslipidemia at middle age, but not in later life, seems to be associated with higher dementia risk in some but not all studies. Results from the Honolulu-Asia Aging Study reported by Saczynski et al. (Am J Epidemiol 2007;165:000–00) suggest that lipoprotein constituents, such as apolipoprotein A-I, a major component of the high density lipoprotein, may be more informative in enlightening the association between lipids and dementia. In this commentary, the epidemiology and biology of apolipoprotein A-I in relation to dementia is reviewed.
Alzheimer disease; apolipoproteins; dementia; lipids
The linear mixed model (LMM), routinely used to describe change over time of outcomes and association with risk factors, assumes that a unit change in any predictor is associated with a constant change in the outcome. When used on psychometric tests, this assumption may not hold. Indeed, psychometric tests usually suffer from ceiling and/or floor effects, and curvilinearity (i.e. varying sensitivity to change).
This work aimed at determining the consequences of such a misspecification when evaluating predictors of cognitive decline. As an alternative to the LMM, two mixed models based on latent processes that handle discrete and bounded outcomes were considered. Models differences were illustrated using four psychometric tests from the cohort PAQUID. Type I error of the Wald test for risk factors regression parameters were then formally assessed in a simulation study. It demonstrated that type I errors in the LMM could be dramatically inflated for some tests so that spurious associations with risk factors were found. In particular confusion between effects on mean level and on change over time was highlighted. The authors thus recommend the use of the alternative mixed models when studying psychometric tests and more generally quantitative scales (quality of life, activities of daily living).
Aged; Cognition Disorders; epidemiology; etiology; Dementia; epidemiology; etiology; Educational Status; France; epidemiology; Humans; Linear Models; Longitudinal Studies; Models, Statistical; Neuropsychological Tests; Psychometrics; Risk Factors; biostatistics; cognition; longitudinal studies; psychometrics; risk factors; statistical models
Sedentary behaviors are linked to adverse health outcomes, but the total amount of time spent in these behaviors in the United States has not been objectively quantified. The authors evaluated participants from the 2003–2004 National Health and Nutrition Examination Survey aged ≥6 years who wore an activity monitor for up to 7 days. Among 6,329 participants with at least one 10-hour day of monitor wear, the average monitor-wearing time was 13.9 hours/day (standard deviation, 1.9). Overall, participants spent 54.9% of their monitored time, or 7.7 hours/day, in sedentary behaviors. The most sedentary groups in the United States were older adolescents and adults aged ≥60 years, and they spent about 60% of their waking time in sedentary pursuits. Females were more sedentary than males before age 30 years, but this pattern was reversed after age 60 years. Mexican-American adults were significantly less sedentary than other US adults, and White and Black females were similarly sedentary after age 12 years. These data provide the first objective measure of the amount of time spent in sedentary behavior in the US population and indicate that Americans spend the majority of their time in behaviors that expend very little energy.
energy metabolism; monitoring; ambulatory; motor activity; obesity; population surveillance
Physiologic studies suggest that sleep restriction has metabolic effects that predispose to weight gain. The authors investigated the association between self-reported usual sleep duration and subsequent weight gain in the Nurses’ Health Study. The 68,183 women who reported habitual sleep duration in 1986 were followed for 16 years. In analyses adjusted for age and body mass index, women sleeping 5 hours or less gained 1.14 kg (95% confidence interval (CI): 0.49, 1.79) more than did those sleeping 7 hours over 16 years, and women sleeping 6 hours gained 0.71 kg (95% CI: 0.41, 1.00) more. The relative risks of a 15-kg weight gain were 1.32 (95% CI: 1.19, 1.47) and 1.12 (95% CI: 1.06, 1.19) for those sleeping 5 and 6 hours, respectively. The relative risks for incident obesity (body mass index: >30 kg/m2) were 1.15 (95% CI: 1.04, 1.26) and 1.06 (95% CI: 1.01, 1.11). These associations remained significant after inclusion of important covariates and were not affected by adjustment for physical activity or dietary consumption. These data suggest that short sleep duration is associated with a modest increase in future weight gain and incident obesity. Further research is needed to understand the mechanisms by which sleep duration may affect weight.
obesity; sleep deprivation; weight gain; women
The authors examined the association between hospital volume of vaginal delivery after cesarean (VBAC) and VBAC failure, uterine rupture, and maternal morbidity. This study was a secondary analysis of a retrospective cohort study from 1995 to 2000. Trained nurses extracted medical records of more than 25,000 women with a prior cesarean delivery from 17 community and tertiary care hospitals. Detailed Information was obtained for each patient. The study sample included 12,844 women with prior cesarean who attempted vaginal delivery with singleton births. Annual hospital VBAC volume was divided into terciles. Primary outcomes included VBAC failure, uterine rupture, and a composite of maternal morbidity. We used multivariable logistic regression to assess the association between hospital VBAC volume and adverse VBAC outcomes controlling for confounders. We did not find evidence of an association between hospital VBAC volume and the likelihood of adverse outcomes in VBAC after adjustment for patient mix. Other risk factors consistent with prior research were identified, including induction of labor, ≥ 2 prior cesarean deliveries, preeclampsia, diabetes and large birth weight. Prior vaginal delivery was protective against adverse VBAC outcomes. The risk of adverse outcomes in VBAC in low volume hospitals was comparable to that in high volume hospitals.
vaginal birth after cesarean; trial of labor; uterine rupture; obstetric labor complication
From a cohort of white, non-Hispanic California Seventh-day Adventists, 99 subjects over age 75 years in 1991 were randomly selected. Dietary habits and educational status had been measured in 1976. Subjects completed the Mini-Mental State Examination (MMSE) in 1991, and at that time, they or caregivers also gave information on current medical problems and drug therapy. Those who ate more calories in 1976 had lower MMSE scores in 1991 (p = 0.03), an association strengthened by excluding those with previous stroke or Parkinson’s disease by 1991. This raises the possibility that higher consumption of calories in middle age may accelerate the decline in cognitive function seen with aging, as apparently occurs in some animals. Less-educated subjects had lower MMSE scores, especially among the very elderly. The statistical model predicts that the negative association between use of psychotropic drugs and MMSE score (p = 0.004) is particularly potent in those cognitively impaired for other reasons. If causal, this suggests that physicians should use these agents very cautiously in such subjects.
caloric intake; dementia; education; psychotropic drugs; Seventh-day Adventists
Hormone replacement therapy (HRT) may reduce lung cancer risk. Dietary boron may have actions similar to those of HRT; however, no previous study has reported the associations between dietary boron intake and lung cancer risk or the joint effects of boron intake and HRT use on lung cancer risk. The authors examined the associations between boron intake and the joint effects of boron intake and HRT on lung cancer risk in women. In an ongoing case-control study in Houston, Texas (July 1995 through April 2005, end date for this analysis), 763 women were diagnosed with lung cancer, and 838 were matched healthy controls with data on both diet and HRT. Multiple logistic regression analyses were conducted to assess the associations between dietary boron and HRT with lung cancer risk. After adjustment for potential confounders, the odds ratios for lung cancer with decreasing quartiles of dietary boron intake were 1.0, 1.39 (95% confidence interval (CI): 1.02, 1.90), 1.64 (95% CI: 1.20, 2.24), and 1.95 (95% CI: 1.42, 2.68) mg/day, respectively, for all women (ptrend < 0.0001). In joint-effects analyses, compared with women with high dietary boron intake who used HRT, the odds ratio for lung cancer for low dietary boron intake and no HRT use was 2.07 (95% CI: 1.53, 2.81). Boron intake was inversely associated with lung cancer in women, whereas women who consumed low boron and did not use HRT were at substantial increased odds.
boron; diet; hormone replacement therapy; lung neoplasms; risk factors; women
The authors used cross-sectional data (2001–2003) to consider the pathway through which past occupational lead exposure impacts cognitive function. They were motivated by studies linking cumulative lead dose with brain volumes, volumes with cognitive function, and lead dose with cognitive function. It was hypothesized that the brain regions associated with lead mediate a portion of the relation between lead dose and cognitive function. Data were derived from an ongoing US study of 513 former organolead manufacturing workers. Magnetic resonance imaging was used to perform a novel analysis to investigate mediation. Volumes associated with cognitive function and lead dose were derived by using registered images and were used in a subsequent mediation analysis. Cumulative lead dose was associated with adverse function in the visuo-construction, executive function, and eye-hand coordination domains. Regarding these domains, there was strong evidence of volumetric mediation of lead’s effect on cognition in the visuo-construction domain and a moderate amount for executive function and eye-hand coordination. A second path-analysis-based approach was also used. To address the possibility that chance associations explained these findings, a permuted analysis was conducted, the results of which supported the mediation inferences. The approach to evaluating volumetric mediation may have general applicability in epidemiologic neuroimaging settings.
epidemiologic factors; epidemiologic methods; lead; magnetic resonance imaging; neurobehavioral manifestations; spectrometry; X-ray emission
Bias (Epidemiology); Health Status; Insurance, Disability; statistics & numerical data; Norway; Socioeconomic Factors
The authors explored the relation of body mass index (BMI; weight (kg)/height (m)2) and weight change to all-cause mortality in the elderly, using data from a large, population-based California cohort study, the Leisure World Cohort Study. They estimated relative risks of mortality associated with self-reported BMI at study entry, BMI at age 21 years, and weight change between age 21 and study entry. Participants were categorized as underweight (BMI <18.5), normal weight (BMI 18.5–24.9), overweight (BMI 25–29.9), or obese (BMI ≥30). Of 13,451 participants aged 73 years (on average) at study entry (1981–1985), 11,203 died during 23 years of follow-up (1981–2004). Relative to normal weight, being underweight (relative risk (RR) = 1.51, 95% confidence interval (CI): 1.38, 1.65) or obese (RR = 1.25, 95% CI: 1.13, 1.38) at study entry was associated with increased mortality. People who were either overweight or obese at age 21 also had increased mortality (RR = 1.17, 95% CI: 1.09, 1.25). Participants who lost weight between age 21 and study entry had increased mortality regardless of their BMI category at age 21. Obesity was significantly associated with increased mortality only among persons under age 75 years and among never or past smokers. This study highlights the influence on older-age mortality risk of being overweight or obese in young adulthood and underweight or obese in later life.
aged; body mass index; body weight changes; longevity; mortality; risk factors
This paper aims to investigate the role of known risk factors in explaining educational differences in breast cancer incidence. Analyses were based on the European Prospective Investigation into Cancer and Nutrition, and included 242,095 women, 433 in situ and 4,469 invasive breast cancers. Reproductive history (age at first full term pregnancy and parity), exposure to endogenous and exogenous hormones, height, and health behaviours were accounted for in the analyses. Relative indices of inequality (RII) for education were estimated using Cox regression models. Higher invasive breast cancer risk was found among women with higher education (RII=1.22: 1.09,1.37). This association was not observed among nulliparous women (RII=1.13: 0.84,1.52). Inequalities in breast cancer incidence decreased substantially after adjusting for reproductive history (RII=1.11: 0.98,1.25), most of the association being explained by age at first full term pregnancy. Each other risk factor explained a small additional part of inequalities in breast cancer incidence. Height contributed most of these factors. When all known risk factors were adjusted for, no association remained between education and invasive breast cancer risk. Inequalities in incidence were more pronounced for in situ breast cancers and remained after adjustment for all known risk factors (RII=1.61: 1.07,2.41), especially among nulliparous women.
breast neoplasms; incidence; education; reproductive history; risk factors
Few studies have examined the impact of weight history. Extant data from the Atherosclerosis Risk in Communities Study were used to compare risk factors for normal-weight (body mass index: 18.5–24.9 kg/m2) adults with a history of weight loss (n = 775) with those for persons with a history of weight maintenance (n = 5,164). In this 1987–1998 US study, the authors also compared risk factors for preobese (body mass index: 25.0–29.9 kg/m2) adults with a history of weight gain (n = 1,296) versus weight maintenance (n = 6,721). They used mixed-models regression to adjust for ethnicity, gender, age, education, field center, smoking, alcohol consumption, follow-up time, and follow-up body mass index. Compared with adults with a history of weight maintenance, adults with a 3-year history of weight loss had more favorable total and low density lipoprotein cholesterol levels and similar glucose, high density lipoprotein cholesterol, and triglyceride levels. In contrast, preobese adults with a 3-year history of weight gain had equivalent glucose and lipid levels at follow-up compared with adults with a history of weight maintenance. These findings suggest that, in addition to current weight, weight history may impact glucose and lipid levels.
glucose; lipoproteins; HDL cholesterol; lipoproteins; LDL cholesterol; obesity; triglycerides; weight gain; weight loss
Few studies have focused on the impact of weight maintenance on cardiovascular disease risk factors or addressed whether changes differ by baseline weight status and medication usage. The authors examined these issues using 9 years of follow-up data on 3,235 men and women from the Atherosclerosis Risk in Communities (ARIC) Study who were aged 45–64 years at baseline (1987–1989). In participants not using medications, glucose (3.0 mg/dl, 95% confidence interval (CI): 2.4, 3.5) and triglycerides (10.1 mg/dl, 95% CI: 8.3, 11.9) increased, while total cholesterol (−9.6 mg/dl, 95% CI: −10.6, −8.6), low density lipoprotein cholesterol (−9.9 mg/dl, 95% CI: −10.9, −9.0), and high density lipoprotein cholesterol (−1.7 mg/dl, 95% CI: −2.1, −1.3) decreased. Systolic blood pressure (7.9 mmHg, 95% CI: 7.3, 8.4) increased, but diastolic blood pressure (−1.1 mmHg, 95% CI: −1.4, −0.7) declined. Normal weight (body mass index: 18.5–<25.0 kg/m2) participants had smaller increases in glucose compared with obese (body mass index: ≥30.0 kg/m2) participants. In contrast, the authors found less favorable changes in total, low density lipoprotein, and high density lipoprotein cholesterol, triglycerides, and diastolic blood pressure among normal weight compared with obese participants who maintained their weight. These patterns were similar across weight status groups regardless of medication usage.
blood pressure; cholesterol; HDL; cholesterol; LDL; glucose; obesity; triglycerides; weight gain; weight loss
A cross-sectional relation between short sleep and obesity has not been confirmed prospectively. We examined the relationship between sleep duration and changes in body mass index (BMI) and waist circumference using the Whitehall II study, a prospective cohort of 10,308 white-collar British civil servants aged 35–55 in 1985–88. Data were gathered in 1997–9 and 2003–4. Sleep duration and other covariates were assessed. Changes in BMI and waist circumference were assessed between the two phases. The incidence of obesity (BMI ≥30 kg/m2) was assessed among non-obese participants at baseline. In cross-sectional analyses (n=5,021), there were significant, inverse associations (p<0.001) between duration of sleep and both BMI and waist circumference. Compared to 7h sleep short duration of sleep (≤5h) was associated with higher BMI (β=+0.82 units; 95% CI 0.38 to 1.26) and waist circumference (β=+1.88 cm; 0.64 to 3.12), and with an increased risk of obesity (ORadj 1.65; 1.22 to 2.24). In prospective analyses, short duration of sleep was not associated with significant changes in BMI (β=−0.06; −0.26 to 0.14) or waist circumference (β=+0.44; −0.23 to 1.12), nor with the incidence of obesity (ORadj 1.05; 0.60 to 1.82). There is no temporal relationship between short duration of sleep and future changes in measures of body weight and central adiposity.
sleep duration; relative weight; body fat distribution; obesity; epidemiology
The Study of Fat Redistribution and Metabolic Change in HIV Infection (FRAM), initiated in 2000, investigates the prevalence and correlates of changes in fat distribution, insulin resistance, and dyslipidemia among human immunodeficiency virus (HIV)-infected men and women compared with a population-based group of control men and women. Between June 2000 and September 2002, 1,480 participants (1,183 HIV-infected persons and 297 controls) were enrolled in FRAM. Measurements taken included whole-body magnetic resonance imaging for quantification of regional fat, anthropometric measurements, central laboratory analysis of metabolites, and assessment of symptoms, sociodemographic factors, and lifestyle. Similar measurements were repeated among FRAM participants 4 years later (FRAM 2) for investigation of the progression of fat distribution changes, insulin resistance, and hyperlipidemia. In FRAM 2, which is ongoing, investigators are also determining the associations of subclinical cardiovascular disease, as measured by carotid intimal-medial wall thickness, with HIV infection, fat distribution changes, insulin resistance, and other proatherogenic changes in serum lipid levels. The demographic characteristics of HIV-infected FRAM men and women were comparable to those reported from a national random sampling of HIV-infected men and women receiving medical care in the United States. The representativeness of the FRAM sample increases its value as a resource for studies on fat distribution, metabolic changes, and atherosclerosis in HIV infection.
body fat distribution; dyslipidemias; HIV infections; insulin resistance; lipodystrophy; metabolism
In vitro data suggest protective roles for vitamins K and D in inflammation. To examine associations between vitamins K and D and inflammation in vivo, we used multiple linear regression analyses, adjusted for age, sex, body mass index, triglyceride concentrations, use of aspirin, lipid lowering and hormone replacement medications, season, and menopausal status. Participants were from the Framingham Offspring Study (n=1381; mean age 59 years; 52% women). Vitamin K status, measured by plasma phylloquinone and phylloquinone intake, was inversely associated with circulating inflammatory markers as a group, and with several individual inflammatory biomarkers (p< 0.01). Percent undercarboxylated osteocalcin, a functional measure of vitamin K status, was not associated with overall inflammation, but was associated with C-reactive protein (p<0.01). Although plasma 25-hydroxyvitamin D was inversely associated with urinary isoprostanes, an oxidative stress indicator (p<0.01), overall associations between vitamin D status and inflammation were inconsistent. The observation that high vitamin K status was associated with lower concentrations of inflammatory markers suggests that a protective role for vitamin K in inflammation merits further investigation.
inflammation; vitamin K; vitamin D; epidemiology