Parity and the Association With Diabetes in Older Women

OBJECTIVE

To examine the relationship of parity with diabetes and markers of glucose homeostasis in older women.

RESEARCH DESIGN AND METHODS

We used data from the female participants in the Cardiovascular Health Study, a longitudinal cohort of adults aged ≥65 years. These data included an assessment of parity (baseline) and fasting serum levels of glucose, insulin, and medication use (baseline and follow-up). We estimated both the cross-sectional relationship of parity with baseline diabetes and the relationship of parity with incident diabetes.

RESULTS

In unadjusted analyses, women with grand multiparity (≥5 live births) had a higher prevalence of diabetes at baseline compared with those with fewer births and with nulliparous women (25 vs. 12 vs. 15%; P < 0.001). In regression models controlling for age and race, grand multiparity was associated with increased prevalence of diabetes (prevalence ratio 1.57 [95% CI 1.20–2.06]); with addition of demographic and clinical factors to the model, the association was attenuated (1.33 [1.00–1.77]). In final models that included body anthropometrics, the association was no longer significant (1.21 [0.86–1.49]). In those without diabetes at baseline, parity was not associated with incident diabetes or with fasting glucose; however, there was a modest association of parity with fasting insulin and homeostasis assessment model of insulin resistance.

CONCLUSIONS

Grand multiparity is associated with diabetes in elderly women in cross-sectional analyses. This relationship seems to be confounded and/or mediated by variation in body weight and sociodemographic factors by parity status. In older nondiabetic women, higher parity does not pose an ongoing risk of developing diabetes.Pregnancy is a time-limited condition; however, there is evidence that child-bearing could have a long-term impact on the health of women. The dramatic alterations in physiology and metabolism associated with the state of pregnancy have sparked questions about the association of child-bearing with the subsequent risk of conditions such as diabetes.Pregnancy induces a state of insulin resistance in a woman''s peripheral tissues. In susceptible nondiabetic women, insulin resistance may be severe enough to cause gestational diabetes mellitus. It is generally assumed that pregnancy-associated insulin resistance resolves after parturition, but subtle metabolic changes could persist, leading to increased risk for diabetes in the future.Researchers examining the relationship between parity and risk of diabetes have come to discordant conclusions. Some studies have suggested a link between higher parity and increased risk of future diabetes (1–5). However, other studies have demonstrated no increased risk of diabetes associated with child-bearing (1,6). In the face of conflicting data, some researchers have suggested that the relationship of increased parity with higher diabetes risk that is observed in some studies is confounded or mediated by other factors, such as body weight and socioeconomic status (6).The aim of our study was to examine the relationship between parity and diabetes in older women, who have the highest prevalence of diabetes. We hypothesized that higher parity was positively associated with the prevalence of diabetes in older women. We studied the influence of potential confounding variables, such as education, race, and alcohol intake, on our hypothesized association between parity and diabetes as well as possible mediators of the association, such as BMI and waist circumference. Finally, we tested the influence of parity on biochemical markers of glucose homeostasis, such as fasting serum glucose and insulin levels, and the homeostasis model assessment of insulin resistance (HOMA-IR) in those without diabetes.