Table 3—

Final multivariate logistic regression models*, by age range: ORs, 95% CIs, and P values for risk factors for self-reported menstrual cycle irregularities

Age rangeCycle length >31 daysPMenstrual bleeding ≥6 daysPHeavy menstrual bleedingPAny menstrual problemsP
<20 years
 Type 1 diabetes1.7 (1.0–2.9)0.031.6 (1.1–2.5)0.021.3 (0.83–2.2)0.242.0 (1.2–3.2)0.006
20–29 years
 Type 1 diabetes2.6 (1.5–4.5)0.0011.7 (1.1–2.6)0.011.7 (1.1–2.8)0.032.5 (1.6–4.1)<0.001
 Ever pregnant2.0 (1.3–3.0)0.0011.7 (1.1–2.5)0.02
30–39 years
 Type 1 diabetes1.5 (0.75–2.9)0.261.3 (0.84–2.0)0.231.1 (0.65–1.8)0.771.5 (0.92–2.3)0.11
 Ever pregnant1.7 (1.0–2.7)0.031.9 (1.3–3.0)0.01
 Oral contraceptive use0.45 (0.24–0.85)0.010.60 (0.37–0.99)0.04
40–49 years
 Type 1 diabetes0.78 (0.29–2.1)0.621.5 (0.86–2.8)0.150.71 (0.37–1.4)0.301.1 (0.63–2.1)0.65
  • *

    * Type 1 diabetes was included in all final models. Variables not reported in Table 3 were nonsignificant and therefore excluded from the final model. Age at menarche and Hashimoto’s status (hypothyroid, euthyroid, or non-Hashimoto’s thyroiditis) at clinic visit were not significant in any model.