Are STK11 polymorphisms a predictor of the response to metformin in polycystic ovarian syndrome?

The aim of this study was to determine the frequencies of different genetic Serine threonine kinase 11 (STK11) variations in women with PCOS and to evaluate possible associations between the genetic polymorphisms of the STK11 gene and the response to metformin in women with polycystic ovary syndrome (PCOS). A prospective longitudinal cohort study of 57 women with PCOS was conducted. The anthropometric measurements, menstrual history, hirsutism, hair loss, acne, and biochemical parameters, in addition to gene testing for STK11 polymorphisms, were documented. Follow-up was arranged after 6 menstrual cycles whilst on oral metformin therapy, (850 mg, twice daily). Of the 120 women who were interviewed, 88 women fulfilled the inclusion criteria and 57 women completed the study. The mean age, weight, height, and BMI were 23.8 years old, 72.1 kg, 159 cm, and 28.6 kg/m2 respectively. The frequencies of the genotypes of intron 1 of the STK11 gene were 26% CC, 44% CG, and 30% GG, and of intron 6 were 52% CC, 37% CT, and 11% TT genotype. There were statistically significant improvements following metformin therapy in menstrual frequency, blood loss, acne, ultrasound findings, and a decrease in BMI, acne, and hirsutism, but not in alopecia. Fasting insulin decreased significantly, but fasting blood sugar did not. There were no significant statistical differences in relation to the LH/FSH ratio, estradiol, FT, 17 OHP and length of menstruation. In relation to the SKT11 gene polymorphisms and metformin administration, there were variable and mostly insignificant differences in the results regarding menstrual regularity, amount of menstrual blood loss, acne, alopecia, ultrasound findings, and hirsutism score. There was a significant difference in relation to alopecia in the Intron 1 subgroups, and in relation to hirsutism score in the Intron 6 subgroups. It was concluded that polymorphisms in the STK11 gene in either Intron 1 or Intron 6 were not predictive of the response to metformin therapy at a dose of 850 mg twice daily, but may have some effect on alopecia and hirsutism.