This analysis shows that Roux-en-Y gastric bypass surgery results in a significant decrease in BMI among Hispanic, NHWs and NHBs with a history or diagnosis of PCOS. Several ethnic group differences in pre-post change in individual cardiometabolic disease risk factors were found. Specifically, while all ethnic groups showed improvement in HbA1c and ALT, the decrease was significant only in Hispanic subjects. Additionally, all ethnic groups showed improvement in TC, LDL and TG one year after surgery. However, improvement in TC and TG were only significant for Hispanics and NHB subjects. Decrease in LDL was only significant in Hispanic and NHW subjects.
Our results are similar to previous studies of much smaller sample sizes that have shown that weight loss after bariatric surgery improves cardiometabolic disease risk among women with PCOS including insulin resistance and dyslipidemia, as well as biochemical features we did not include such as hyperandrogenism and oligomenorrhea[8
]. Specifically, Escobar-Morreale et al[8
] followed 12 Caucasian women of European ancestry with PCOS after bariatric surgery and found significant improvements in hirsutism and normalization of serum androgens in 91% of subjects at follow up (mean 12 mo, range 7-26 mo). All patients had regular menses after weight loss and 10 subjects had confirmed ovulation. They also found normalization of insulin sensitivity based on homeostasis model assessment (HOMA) in all patients. Similarly, Eid et al[9
] followed 24 American women, whom were primarily Caucasian, with PCOS after Roux-en-Y gastric bypass (mean follow up 27 mo, range 12-57 mo). All subjects had normalization of menses and 77% had significant improvement or resolution of hirsutism. Eleven of the 24 subjects had type 2 diabetes prior to surgery and all 11 were normoglycemic at follow up without glucose lowering medications. Likewise, eleven patients with dyslipidemia prior to surgery no longer required cholesterol lowering medications at follow up. The most recent study by Jamal et al followed 20 American women with PCOS after Roux-en-Y gastric bypass (mean follow up 46.7 mo, range 15-123 mo)[10
]. They found similar improvements in menses, hirsutism and type 2 diabetes. Six patients that desired pregnancy were able to conceive. These studies indicate weight loss through bariatric surgery significantly improved symptoms of PCOS and associated cardiometabolic disease risk and confirm our findings.
Hispanic ethnicity is associated with an increased cardiometabolic disease risk. In the Diabetes Prevention Trial, Hispanic adults with impaired glucose tolerance were found to have a higher HbA1c and HOMA after adjusting for BMI compared with white subjects with similar fasting plasma glucose levels[15
]. Similarly, in the Nurse’s Health Study the relative risk of type 2 diabetes among Hispanic women was 2.18 compared to white women after adjusting for BMI[13
]. In addition, relative risk for type 2 diabetes is higher in Hispanics than in African-Americans[13
]. Obesity further amplifies this risk; it has been reported that for every 5 point increase in BMI the relative risk for diabetes in Hispanic women is 2.36 vs
1.96 in NHW women[13
]. Furthermore, obese Hispanic women are at a higher risk of diabetes compared to NHW and NHB women. Therefore, weight loss in obese Hispanic women with PCOS may improve the risk for overt diabetes more substantially compared to NHB and NHW subjects. Our results here showed significant ethnic group differences in the post-surgery improvement in HbA1c. While HbA1c improved in all groups, the improvement was only significant among Hispanic women with PCOS. This specific finding suggests that obesity may impact glucose tolerance more in Hispanic women with PCOS vs
Hispanics also have a higher prevalence of NAFLD which is associated with obesity, insulin resistance and increased metabolic risk[11
]. NAFLD represents a spectrum of fat accumulation in the liver from steatosis to cirrhosis and is the most common cause of elevated liver enzymes[16
]. The estimated United States prevalence of NAFLD is approximately 25% in the general population, but has been found to be as high as 45% in some Hispanic populations vs
33% among NHW and 25% among NHB[11
]. The prevalence of hepatic steatosis on ultrasound among NHW women with PCOS is 55% and may be as high as 90% in some obese cohorts[17
]. Hispanic women with PCOS also had a higher prevalence of NAFLD compared to Caucasian subjects[11
]. Women with PCOS have a low prevalence of elevated transaminases despite radiographic evidence of hepatic steatosis. Gambarin-Gelwan et al[18
] determined that only 15% of women with PCOS and steatosis on ultrasound had abnormal liver enzymes. We found in our population of women with PCOS that Hispanic and NHW subjects had a higher baseline ALT compared to NHB subjects. Post-surgery, Hispanic women with PCOS had a significant decrease ALT, whereas the decrease in ALT in NHW and NHB subjects was not significant. This decreased in ALT in the Hispanic population may indicate improvement of fatty infiltration after surgery and therefore, weight loss in obese Hispanic women with PCOS may have a greater impact on hepatic steatosis compared to NHW and NHB subjects.
We also found differential improvements in cholesterol among the Hispanic and NHB subjects. The majority of American women with PCOS have a lipid abnormality[19
]. Most display an atherogenic lipid profile including high triglyceride concentrations, high LDL and low HDL[20
]. Browning et al[11
] found in a sample of 12 women the majority with PCOS that required cholesterol lowering medication prior to surgery were able to discontinue medication at follow up based on improvements in total cholesterol and triglycerides. We found that all ethnic groups showed improvement in total cholesterol, LDL and TG after surgery. However, total cholesterol and triglycerides showed significant improvement only for Hispanics and NHB subjects, and improvement in LDL was only significant for Hispanics and NHW subjects one year after surgery. We also found NHB subjects had significantly lower baseline triglycerides compared to Hispanics and NHW subjects. This is consistent with other adult[21
] and adolescent studies which found lower triglycerides levels among NHB subjects compared to Hispanics and NHW subjects[24
In conclusion, morbidly obese women with PCOS who have undergone Roux-en-Y gastric bypass surgery show improvement in cardiometabolic disease risk at one year after the procedure. All women demonstrated a decrease in cardiometabolic disease risk factors including BMI, HgA1c, ALT, TC, LDL and TG. However, only Hispanic women showed a significant decreasing HgA1c and ALT, TC, LDL and TG one year after surgery. These ethnic group differences suggest there may be more comprehensive benefits in terms of cardiometabolic disease risk reduction after bariatric surgery in Hispanic women with PCOS vs other ethnic groups.