3 | Results
Baseline characteristics of patients are presented in Table 1. A total of 2,541,550 women were eligible, of whom 18,375 (0.72%) were diagnosed with UL. The mean age was 29.70 y, and mean BMI was 21.31 kg/m2. Women with UL were older; had higher BMI, blood pressure, FPG, total cholesterol, TG, and LDL cholesterol; and had higher prevalence of hypertension, dyslipidemia, and IFG, as well as lower HDL cholesterol, than those without UL. However, women with UL were revealed to have a lower rate of current smoking and heavy drinking status as compared to those without UL. There was no significant difference in CKD prevalence or regular exercise frequency between women with UL and those without UL.
Over a median 7.45 years of follow-up, 23,829 women (0.94%) were diagnosed with type 2 diabetes mellitus (Table 2). The incidence rate of type 2 diabetes mellitus in women with UL (1.805/1,000 person-years) was higher than that in those without UL (1.289/1000 person-years) (P< 0.0001). The cumulative incidence of type 2 diabetes mellitus in women with UL was higher than that in those without UL (P = 0.0026) (Fig. 1A). The unadjusted HR for type 2 diabetes mellitus in women with UL was 1.403 (95%CI 1.236-1.593) compared to that in those without UL. Although the HR for type 2 diabetes mellitus was slightly decreased after adjustment for age, smoking status, alcohol consumption, and regular exercise (model 1), women with UL still showed an elevated HR for type 2 diabetes mellitus(HR 1.195, 95%CI 1.053-1.358). In multivariable-adjusted model (model 2), the HR for type 2 diabetes mellitus in women with UL was 1.216 (95%CI 1.071-1.382).
Subgroup analyses stratified by age, BMI, smoking status, alcohol consumption, regular exercise, and having hypertension, dyslipidemia, and CKD were performed (Table 3). Women with UL showed a higher risk for type 2 diabetes mellitus than women without UL in various subgroups, except in those with BMI ≥25 kg/m2 and a history of CKD.
Women with UL who underwent myomectomy were older and had higher BMI than those with UL who did not undergo myomectomy (Supplementary Table 1). There was no significant difference in other baseline characteristics between the two groups. Compared with women without UL, women with UL who did not undergo myomectomy had a 1.505 times (95%CI 1.297-1.748) higher risk for type 2 diabetes mellitus, as opposed to no increased risk for type 2 diabetes mellitus in those with UL who underwent myomectomy (Table 2). Women with UL who did not undergo myomectomy still had an elevated HR for type 2 diabetes (HR 1.287, 95%CI 1.108-1.495) after adjustment for age, smoking status, alcohol consumption and regular exercise (model 1). In the multivariable-adjusted model (model 2), the HR for type 2 diabetes in women with UL who did not undergo myomectomy was 1.328 (95% CI 1.143-1.542). However, risk for type 2 diabetes mellitus was not increased in women with UL who underwent myomectomy in models 1 and 2. The cumulative incidence of type 2 diabetes mellitus in women with UL who did not undergo myomectomy was higher than that in those with UL who underwent myomectomy (P = 0.0357) (Fig. 1B).