Abstract
AIM: To test the hypothesis that delayed menarche is associated with an increased microvascular complication risk among women with Type 1 diabetes. METHODS: We studied the female participants of an ongoing prospective study of childhood-onset Type 1 diabetes diagnosed during the period 1950-1980. Of 325 women, we included data from 315 who had reached menarche by the study baseline (1986-1988) and who self-reported their age at menarche. Both cross-sectional and prospective analyses over the 25-year follow-up were used to assess the relationship of age at menarche with the prevalence, incidence and cumulative incidence of microvascular complications, comprising overt nephropathy, proliferative retinopathy and confirmed distal symmetric polyneuropathy. RESULTS: In cross-sectional analyses at baseline, the odds of overt nephropathy increased 1.24 times (P=0.02) with each annual increase in age at menarche, and 3.2 times (P=0.009) in those with delayed menarche compared with women with normal menarche onset, after adjustment. Similarly, the cumulative incidence of overt nephropathy increased 1.16 times (P=0.01) with each older year of menarche and women with delayed menarche were at twofold increased risk of overt nephropathy (hazard ratio 2.30, P=0.001) compared with women with normal menarche onset. However, age at menarche was not significantly associated with either proliferative retinopathy or confirmed distal symmetric polyneuropathy after adjusting for covariates. CONCLUSIONS: Age at menarche was significantly associated with the prevalence and cumulative incidence of overt nephropathy, but not with proliferative retinopathy or confirmed distal symmetric polyneuropathy in Type 1 diabetes. Women with delayed menarche may therefore be targeted for early screening and timely interventions to prevent the development of nephropathy.