Influence of body mass index and age on the grade of hair growth in hirsute women of reproductive ages.

The relationships between the hair growth in different body regions, body mass index (BMI) and age were studied in 225 women of reproductive ages referred for hirsutism. The regularity of the cycles was registered, and 109 of the patients were interviewed for their maximum weight, teenage obesity, and age of menarche. The serum androgens were measured in the follicular phase. The results indicate that facial hirsutism is associated with BMI (rho = 0.41, P less than 0.001) independently of age and the testosterone (T) to sex hormone-binding globulin (SHBG) ratio. Facial hirsutism is also correlated with age (rho = 0.37, P less than 0.001) irrespective of BMI (rho = 0.26, P less than 0.001) or the T/SHBG ratio (rho = 0.43, P less than 0.001). In contrast, the hair growth on trunk area is related to the T/SHBG ratio (rho = 0.35, P less than 0.001) but not to BMI or age when the correlations are adjusted for the grade of hyperandrogenemia. The women with severe facial hirsutism had a higher maximum weight (P less than 0.001) and more teenage obesity (P less than 0.01) than other hirsute patients. They also had a slightly earlier menarche compared with their agemates than the women with mild or absent facial hair (P less than 0.05). The data suggest differences in the regulation of hair growth between the face and trunk areas.