This study belongs to the implementation project of the Programme for the Prevention of T2D in Finland 2003–2008 (FIN-D2D).16
In total, 400 primary healthcare centres and occupational healthcare outpatient clinics participated in the programme.15
One of the principal aims of the FIN-D2D was to screen for individuals at high risk of T2D,16
by using a modified Finnish Diabetes Risk Score test (FINDRISC),15
with a cut-off point of 15 or more and history of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), cardiovascular events or gestational diabetes.15
Lifestyle counselling was offered to high-risk individuals in order to reduce their T2D risk. There was no randomisation, instead an opportunistic screening process was conducted and participants volunteered, thus they provided oral consent for willingness of taking part in this national programme carried out within primary care to prevent diabetes in the normal clinical settings. Because from the participants’ point of view, they were not participating in a ‘study’; there was no need to ask for a separate written informed consent from them. Nevertheless, all participants received written information on the FIN-D2D and they were informed of the data collection. As for the ethical approval, the National Public Health Institute applied for and obtained the permission from the Ministry of Social Affairs and Health for the purposes of evaluation and research to collect register-based morbidity data on FIN-D2D participants from primary care information systems.
Lifestyle counselling was performed either in group sessions or individually. Local resources had an effect on the number and frequency of intervention visits. However, individual visits were planned according to individuals’ needs, and the following topics and items were included: weight control, meal frequency and quality, for example, use of dietary fibre, fat and salt, physical activity, smoking, alcohol use and diabetes as a disease in general. Group sessions were mainly weight maintenance or exercise groups and lectures concerning diabetes and lifestyle changes.15
After identification individuals at high risk for T2D were referred to health check-ups. They were asked to fill in a questionnaire on background health and lifestyle information before the health check-up. Local nurses in primary healthcare measured weight (to the nearest 0.1 kg), height (to the nearest cm), systolic and diastolic blood pressure (BP) (mm Hg) and gave brief motivation-building and counselling for lifestyle changes,17
based on the principles of the Finnish Diabetes Prevention Study (DPS).20
Body mass index (BMI) was calculated by weight divided by height (kg/m2
Weight loss during follow-up was dichotomised by using median to ≤0.80 or >0.80 kg for both genders. Oral glucose tolerance test (OGTT) was carried out in the morning after overnight fast with a glucose load of 75 g. Fasting and 2 h samples were collected from venous or capillary blood samples. At the baseline 80% and at the follow-up 85% were plasma venous samples. Corresponding figures for capillary samples were 20% and 15%, respectively.15
Glucose tolerance status was classified by using World Health Organization (WHO) 1999 criteria.21
Enzymatic methods were performed locally to determine plasma lipids and lipoproteins (mmol/l).15
The use of lipid-lowering medication, antihypertensive and coronary artery disease medication was verified at the health check-up at baseline from prescriptions if possible. Individuals whose lipid-lowering medication had been initiated 120 days before the first visit or before the midway of the 1-year follow-up (no later than 270 days after the first visit) were regarded as users at the baseline. Statins are used almost exclusively for the treatment of dyslipidaemias in Finland.22
In 2010, 93 035 individuals had reimbursement of drug costs under the Special Refund Category for dyslipidaemia associated with chronic coronary artery disease for HMG-CoA reductase inhibitors, while the corresponding numbers for fibrates and bile acid sequestrates were only 573 and 104, respectively.23
Thus, we had a good reason to assume that lipid-lowering medication included statins only. If an individual used antihypertensive or coronary artery disease medication or both at the baseline he/she was classified as a user. CVD (heart failure, angina pectoris, coronary artery disease, myocardial infarction, heart bypass surgery and angioplasty) were asked by the questionnaire. If an individual had one of these diseases or abnormalities, he/she was considered as having CVD.
In total, 10 149 (3379 men and 6770 women) high-risk individuals aged 18–87 years were contacted between 17 January 2004 and 28 August 2007; 8353 of them had OGTT. Of them 5523 individuals participated in the follow-up visits, and 1-year follow-up information (defined by visits between 17 January 2005 and 12 June 2008) was available for 3880 individuals (1339 men and 2541 women). Of these individuals, 444 had screen-detected T2D, while 638 individuals did not participate in the OGTT at the baseline and were excluded from this study. Thus 2798 individuals participated in this study.15
There were altogether 484 (17.3%) statin users at baseline among them. Twenty-six of them (5.4%) had started statin use no later than 270 days after the first visit.
Statistical analyses were performed by using SAS (V.9.2) for Windows and they were based on percentage distributions and χ2 test and independent sample t test. Analysis of covariance (ANCOVA) was used to study the differences between the statin users and non-users in changes of fasting glucose values during the follow-up after adjusting for age, sex, weight, CVD disease, use of antihypertensive and/or coronary artery disease medication and fasting glucose at baseline and 1-year weight change as a continuous variable. Furthermore, separate logistic regression analyses were conducted for statin users and non-users to study the effect of weight loss (≤0.8 or >0.8 kg) on T2D risk after adjusting for age, sex, weight, CVD diseases, use of above-mentioned medication and glucose tolerance and at the baseline.