This appears to contrast with previous studies that have reported increased serum levels of IGF1 in PCOS patients in comparison to controls [43,44]; however, in a meta-analysis of 20 studies, 5 of these showed higher IGF1 levels in the controls and when stratified for BMI less than or equal to 29 kg/m2, IGF1 levels were significantly higher in the control populations, suggesting that the serum IGF1 levels between groups depends on the proportion of subjects with a BMI less than or greater than 29 kg/m2 [45]. This evidence concerns the gene IGF1 and polycystic ovary syndrome.