Difference in body weight between American and Italian women with polycystic ovary syndrome: influence of the diet

Background: The study aim was to determine differences in body mass in two populations of women (USA and Italy) with polycystic ovary syndrome (PCOS), and to assess the effect of diet on body mass and cardiovascular risk factors. Methods: Pools of women with PCOS from the USA (n=343) and Italy (n=301), seen between 1993 and 2001, <LF>were available for assessment. From these populations, 20 women who were seen consecutively in 2001 at each site had detailed analyses of diet and cardiovascular risk factors. Results: In the entire group, American women had a significantly higher body mass compared with Italian women (P<0.01). Also, the 20 women consecutively evaluated in the USA had a significantly higher mean (+/-SD) body mass index (40.3+/-1.0 kg/m(2)) than in Italy (29.7+/-1.0 kg/m(2)). US women had worse insulin resistance, lower levels of high-density lipoprotein-cholesterol (HDL-C) (P<0.01) and higher levels of triglycerides (P<0.01). Dietary analysis in the two groups indicated that the total daily calorific intake was similar (USA 2277 +/- 109; Italy 2325 +/- 68 Kcal), with no appreciable differences in dietary content of protein, carbohydrate and fat. However, the dietary saturated fat content was significantly higher in US women (31.9+/-3 versus 18.2+/-2 g/day, P<0.01). Saturated fat intake correlated negatively with HDL-C (P<0.01). Conclusions: Among women with PCOS, body mass was significantly higher in US women compared with Italian women. However, total calorie intake and dietary constituents were similar, except for a higher saturated fat in US women. It is hypothesized that diet alone does not explain differences in body mass; genetic and lifestyle factors likely contribute. An increased saturated fat intake may worsen the cardiovascular risk profile.