TSH levels associated with slimming pill use in a population-based study of Brazilian women

To determine the consumption of slimming pills (SP) and its association with TSH levels.

A survey was carried out in Rio de Janeiro (about 5 million inhabitants), Brazil, from June 2004 to April 2005. Households (1,500) were selected using three-stage probability sampling. Women were asked about use of SP, and blood sample was collected. Women were classified as users of SP any time in life, but not in previous two months (n = 293), current users (n = 150), and never users (n = 853). Weighted multivariate regression analyses compared TSH levels among these groups of users.

The frequency of use of SP any time in life was 34% and the use in the previous two months was 11%. Both frequencies were greater among younger and obese women, and among those of high socioeconomic level (p-value < 0.001). TSH level was statistically lower among current users of SP (1.96 mUI/ml; 95%CI = 1.93-1.98) compared to previous users 2.83 mUI/ml (95%CI = 2.13-3.02) and never users 2.59 mUI/ml (95%CI = 2.20-3.21). These differences were still statistically significant after adjusting for age and body mass index.

Use of SP decreased TSH levels among Brazilian women.