A systematic review and meta-analysis of follicle-stimulating hormone levels among men with type 2 diabetes

Background There are some studies with inconsistent results regarding the association between follicle stimulating hormone (FSH) levels and type 2 diabetes (T2DM) among men. We performed a systematic review and meta-analysis that explored the FSH levels among men with and without T2DM. Results Twenty studies with a total sample size of 4,208 (2167diabetic men and 2041 control) were included in this meta-analysis. The standardized mean differences (SMD) in men who had T2DM compared to control group were -0,237 (CI95%: -0,582 to 0,108; P = 0.17; I2: 95,83%; Egger's test: 0.06; Begg's test: 0.15). This finding was significant after sensitivity analysis. Among Asian studies SDM was -0,955 (CI95%: -1,630 to -0,279; p = 0.006; I2: 96.91%; Egger's test: 0.03; Begg's test: 0.01), with diabetic men had lower FSH than control group. African diabetic males the FSH levels was not different than non-diabetics (SMD: 0,386; CI95%: -0,0401 to 0,813; p = 0.07; I2: 94.26%; Egger's test: 0.31; Begg's test: 0.21). Also, among European men the FSH levels was significantly different than non-diabetics (SMD: 0,273; CI95%:0,0960 to 0,450; p = 0.003; I2: 18.41%; Egger's test: P < 0,0001; Begg's test: 0.31). Conclusion Our meta-analysis of the current literature suggests that serum FSH levels are significantly lower in Asian men diagnosed with T2DM compared to their non-diabetic counterparts. This finding highlights a potential association between altered FSH concentrations and the pathogenesis of T2DM. Future studies should aim to unravel these mechanistic pathways and to assess the clinical utility of FSH as a biomarker for T2DM risk assessment and management in the male population.