PTEN Regulation of Insulin Resistance Is Sex Specific
(HealthDay News) — Skeletal muscle phosphatase and tensin homolog deleted on chromosome 10 (PTEN) regulates insulin resistance in a sex-specific manner, according to a study published online March 17 in Scientific Reports.
M. Constantine Samaan, M.D., from McMaster University in Hamilton, Canada, and colleagues examined whether PTEN regulates insulin resistance in a sex-specific manner. Muscle biopsies from participants in the Molecular Study of Health and Risk in Ethnic Groups were used to examine sex differences in PTEN expression in a cross-sectional study. PTEN gene expression was assessed using quantitative real-time polymerase chain reaction assay in 53 participants, and western blotting detected total and phosphorylated PTEN protein in 36 participants.
The researchers found that the fat mass percentage was higher for women than men (40.25 ± 9.9 percent versus 27.6 ± 8.8 percent; P < 0.0001). Homeostatic model assessment-insulin resistance (HOMA-IR) was comparable in men and women (2.46 ± 2.05 and 2.34 ± 3.06; P = 0.59). After adjustment for age, ethnicity, HOMA-IR, fat mass, and sex, women had significant downregulation of PTEN gene expression (P = 0.01) and upregulation of PTEN protein phosphorylation (P = 0.001) compared with men.
"We conclude that the downregulation of muscle PTEN may explain the retention of insulin sensitivity with higher adiposity in women compared to men," the authors write.