Caren G. Solomon

Obesity and mortality: a review of the epidemiologic data.

At least one-third of Americans are obese, as defined by body mass indexes corresponding to body weight > or = 120% of ideal body weight, and this figure is rising steadily. Women and nonwhites have particularly high rates of obesity. Obesity greatly increases risks for many serious and morbid conditions, including diabetes mellitus, hypertension, dyslipidemia, coronary artery disease, and some cancers. Obesity is clearly associated with increased risk for mortality, but there has been controversy regarding optimal weight with respect to mortality risk. We review the literature concerning obesity and mortality, with reference to body fat distribution and weight gain, and consider potential effects of sex, age, and race on this relation. We conclude that when appropriate adjustments are made for effects of smoking and underlying disease, optimal weights are below average in both men and women; this appears to be true throughout the adult life span. Central obesity, most commonly approximated by the waist-to-hip ratio, may be particularly detrimental, although this requires further study. Weight gain in adulthood is also associated with increased mortality. These observations support public health measures to reduce obesity and weight gain, including recent recommendations to limit weight gain in the adult years to 4.5 kg (10 lb).

THE EPIDEMIOLOGY OF POLYCYSTIC OVARY SYNDROME: Prevalence and Associated Disease Risks

Polycystic ovary syndrome is a common problem affecting approximately 5% of women of reproductive age when defined by clinical features of anovulation and hyperandrogenism. Metabolic derangements associated with this condition may predispose to a range of diseases with attendant morbidity and mortality risks. In general, available data support significantly increased rates of type II diabetes mellitus, dyslipidemia, and endometrial cancer in PCOS that are not completely explained by obesity; data also suggest that rates of hypertension, gestational diabetes, and pregnancy-induced hypertension may likewise be increased, although the extent to which obesity mediates these risks is not clear. The increased prevalence of several cardiovascular risk factors in PCOS and limited cross-sectional data suggest that cardiovascular disease should be more likely in PCOS, but prospective data are lacking to confirm this supposition. Limited data have suggested an association between PCOS and ovarian cancer risk and require further study. The present data do not support an increased risk for breast cancer in this condition. Long-term prospective data are clearly needed to better delineate the nature and magnitude of disease risks associated with PCOS, with appropriate adjustment for associated obesity. Such information is a necessary background for understanding the role of established and emerging PCOS therapies, including oral contraceptives, intermittent progesterone, ovulation induction agents, and insulin sensitizers, in modifying such risks. In the meantime, close follow-up of women with PCOS and encouragement of lifestyle practices likely to reduce disease risks, such as regular exercise and weight control, should be standard practice.

Brief Review: Hypertension in Pregnancy : A Manifestation of the Insulin Resistance Syndrome?

Pregnancy-induced hypertension (PIH), which includes both gestational hypertension and preeclampsia, is a common and morbid pregnancy complication for which the pathogenesis remains unclear. Emerging evidence suggests that insulin resistance, which has been linked to essential hypertension, may play a role in PIH. Conditions associated with increased insulin resistance, including gestational diabetes, polycystic ovary syndrome, and obesity, may predispose to hypertensive pregnancy. Furthermore, metabolic abnormalities linked to the insulin resistance syndrome are also observed in women with PIH to a greater degree than in normotensive pregnant women: These include glucose intolerance, hyperinsulinemia, hyperlipidemia, and high levels of plasminogen activator inhibitor-1, leptin, and tumor necrosis factor-alpha. These observations suggest the possibility that insulin resistance may be involved in the pathogenesis of PIH and that approaches that improve insulin sensitivity might have benefit in the prevention or treatment of this syndrome, although this requires further study.

High body mass index and hypercholesterolemia: risk of hypertensive disorders of pregnancy.

OBJECTIVE To examine the relationship between pregravid body mass index (BMI), elevated cholesterol level, and the development of hypertensive disorders of pregnancy. METHODS We studied 15,262 women who gave birth between 1991 and 1995. Pregravid exposures including BMI and self-reported history of elevated cholesterol were ascertained by biennial mailed questionnaires. Gestational hypertension or preeclampsia was confirmed by medical record review according to standard criteria. Proportional hazards analysis was used to adjust for potential confounding variables. RESULTS We confirmed 216 cases of gestational hypertension and 86 cases of preeclampsia. The risk of gestational hypertension increased as pregravid BMI increased (P < .01). Compared with women with a pregravid BMI of 21-22.9 kg/m2, the relative risk (RR) of gestational hypertension was 1.6 (95% confidence interval [CI] 1.0, 2.3) for women with BMI of 23-24.9 kg/m2, 2.0 (95% CI 1.3, 3.0) for BMI 25-29.9 kg/m2, and 2.6 (95% CI 1.6, 4.4) for BMI over 30 kg/m2. Leaner women (BMI less than 21 kg/m2) had a reduced risk (RR 0.7, 95% CI 0.4, 1.0). For preeclampsia, the RR of women with pregravid BMI over 30 kg/m2 was 2.1 (95% CI 1.0, 4.6) (P for trend 0.09). A history of elevated cholesterol was not associated with the risk of gestational hypertension (RR 0.9, 95% CI, 0.6, 1.4). In contrast, the RR of preeclampsia in women with a history of elevated cholesterol was 2.0 (95% CI 1.2, 3.3). CONCLUSION Pregravid BMI and hypercholesterolemia could identify women at higher risk for hypertensive disorders during pregnancy.

A prospective study of dietary patterns, meat intake and the risk of gestational diabetes mellitus

Aims/hypothesisThe aim of this study was to prospectively examine whether dietary patterns are related to risk of gestational diabetes mellitus (GDM).MethodsThis prospective cohort study included 13,110 women who were free of cardiovascular disease, cancer, type 2 diabetes and history of GDM. Subjects completed a validated semi-quantitative food frequency questionnaire in 1991, and reported at least one singleton pregnancy between 1992 and 1998 in the Nurses’ Health Study II. Two major dietary patterns (i.e. ‘prudent’ and ‘Western’) were identified through factor analysis. The prudent pattern was characterised by a high intake of fruit, green leafy vegetables, poultry and fish, whereas the Western pattern was characterised by high intake of red meat, processed meat, refined grain products, sweets, French fries and pizza.ResultsWe documented 758 incident cases of GDM. After adjustment for age, parity, pre-pregnancy BMI and other covariates, the relative risk (RR) of GDM, comparing the highest with the lowest quintile of the Western pattern scores, was 1.63 (95% CI 1.20–2.21; ptrend=0.001), whereas the RR comparing the lowest with the highest quintile of the prudent pattern scores was 1.39 (95% CI 1.08–1.80; ptrend=0.018). The RR for each increment of one serving/day was 1.61 (95% CI 1.25–2.07) for red meat and 1.64 (95% CI 1.13–2.38) for processed meat.Conclusions/interpretationThese findings suggest that pre-pregnancy dietary patterns may affect women’s risk of developing GDM. A diet high in red and processed meat was associated with a significantly elevated risk.

Glucose intolerance as a predictor of hypertension in pregnancy.

Insulin resistance is associated with and may be causal in essential hypertension, but the relation between insulin resistance and hypertension arising de novo in pregnancy is unclear. Transient hypertension of pregnancy (new-onset nonproteinuric hypertension of late pregnancy) is associated with a high risk of later essential hypertension and thus may have similar pathophysiology. To assess the association between glucose intolerance and subsequent development of proteinuric and nonproteinuric hypertension in pregnancy in women without underlying essential hypertension or overt glucose intolerance, we performed a retrospective case-control study comparing glucose levels on routine screening for gestational diabetes mellitus among women subsequently developing hypertension. Women who developed hypertension in pregnancy (n = 97) had significantly higher glucose levels on 50-g oral glucose loading test (P < .01) and a significantly higher frequency of abnormal glucose loading tests (> or = 7.8 mmol/L) (P < .01) than women who remained normotensive (n = 77). Relative glucose intolerance was particularly common in women who developed nonproteinuric hypertension. Women who developed hypertension also had greater prepregnancy body mass index (P < or = .0001) and baseline systolic and diastolic blood pressures (P < or = .0001 for both), although all subjects were normotensive at baseline by study design. However, after adjustment for these and other potential confounders, an abnormal glucose loading test remained a significant predictor of development of hypertension (P < .05) and, specifically, nonproteinuric hypertension in pregnancy (P < .01). Among a subgroup of women in whom insulin levels were also measured (n = 80), there was a nonsignificant trend toward higher insulin levels in women developing hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Predictors of excessive and inadequate gestational weight gain in Hispanic women.

Factors influencing gestational weight gain are incompletely understood, particularly among Hispanic women. We assessed medical, sociodemographic, behavioral, and psychosocial predictors of overall gestational weight gain, as well as gains below, within, or above the range recommended by the Institute of Medicine (IOM) within a prospective study of 770 Hispanic (predominantly Puerto Rican) prenatal care patients at a large tertiary care facility in Western Massachusetts. One third of women gained within the recommended range, 22% gained below, and 45% gained above the range. In multivariate analysis, women in the highest category of BMI (Ptrend < 0.001) and parity (Ptrend < 0.001) gained on average 9 lbs less than those in the lowest category. Increasing time in residence in the continental United States (Ptrend < 0.01) as well as a number of prenatal care visits (Ptrend = 0.03) were positively associated with weight gain. Overweight women (odds ratio (OR) = 2.2, 95% confidence interval (CI) 1.3, 3.8) and those over age 30 years (OR = 2.5, 95% CI 1.2, 5.0) were more likely to gain above the IOM range as compared to normal‐weight women and those aged 20–24, respectively. Women with <10 years of residence in the United States were 50% less likely to gain above the IOM range as compared to third‐generation women (95% CI 0.3, 0.9). Findings identify determinants of gestational weight gain which can form the basis of targeted interventions in this rapidly growing ethnic group.

Prepregnancy body mass index, gestational weight gain, and risk of hypertensive pregnancy among Latina women

OBJECTIVE Prepregnancy body mass index (BMI) and gestational weight gain have been associated with hypertensive disorders of pregnancy, but previous studies have included few Latinas, a group at increased risk. STUDY DESIGN We examined these associations in the Latina Gestational Diabetes Mellitus Study, a prospective cohort of 1231 women conducted from 2000 to 2004. RESULTS In multivariable analysis, obese women (BMI > 29.0 kg/m(2)) had 2.5 times the risk of hypertensive pregnancy (95% confidence interval [CI], 1.3-4.8) and 2.7 times the risk of preeclampsia (95% CI, 1.2-5.8), compared with women whose BMI was 19.8 to 26.0 kg/m(2). Women with excessive gestational weight gain had a 3-fold increased risk of a hypertensive disorder of pregnancy (95% CI, 1.1-7.2) and a 4-fold risk of preeclampsia (95% CI, 1.2-14.5), compared with women achieving weight gain guidelines. CONCLUSION These findings suggest prepregnancy obesity and excessive weight gain are associated with hypertension in pregnancy in a Latina population and could be potentially modifiable risk factors.

Physical activity and gestational diabetes mellitus among hispanic women

OBJECTIVE Studies in predominantly non-Hispanic white populations have suggested that physical activity during pregnancy is associated with a reduced risk of gestational diabetes mellitus (GDM). There are few such studies in Hispanic women, a group at increased risk for GDM. METHODS We conducted a prospective cohort study of household/caregiving, occupational, sports/exercise, and active living habits and the risk of GDM among 1006 Hispanic (predominantly Puerto Rican) prenatal care patients in western Massachusetts from 2000 to 2004. Prepregnancy, early pregnancy, and midpregnancy physical activity was assessed using the Kaiser Physical Activity Survey. RESULTS A total of 33 women (3.3%) were diagnosed with GDM, and 119 women (11.8%) were diagnosed with abnormal glucose tolerance. There were no significant associations between GDM risk and occupational and active living activities in prepregnancy, early pregnancy, and midpregnancy or with a change in levels of household/caregiving, occupational, and active living activities from prepregnancy to during pregnancy. However, after controlling for age and prepregnancy body mass index (BMI), women in the highest quartile of prepregnancy (OR = 0.2, 95% CI 0.1-0.8, p(trend) = 0.03) and midpregnancy (OR = 0.2, 95% CI 0.1-0.8, p(trend) = 0.004) household/caregiving activities as well as midpregnancy sports/exercise (0.1, 95% CI 0.0-0.7, p(trend) = 0.12) had a reduced risk of GDM compared with women in the lowest quartile. CONCLUSIONS Findings in this Hispanic population, although based on small numbers of cases, are consistent with prior research among predominantly non-Hispanic white populations.

The association between magnesium intake and fasting insulin concentration in healthy middle-aged women.

Objective: We assessed the association between magnesium intake and fasting insulin levels in a large cohort of women. Methods: Female nurses free of diabetes, cardiovascular diseases and cancer from the Nurses Health Study provided blood samples between 1989–1990. We selected a sub-sample of 219 women for this analysis. Magnesium intake was assessed by a food frequency questionnaire in 1990 and categorized into quartiles. Cross-sectional geometric means of fasting insulin concentrations by quartiles of magnesium intake were obtained with Generalized Linear Model and adjusted for several risk factors and lifestyle characteristics. Results: After adjustment for age, body mass index (BMI), total energy, physical activity, hours per week spent sitting outside work, alcohol intake, smoking, and family history of diabetes, magnesium intake was inversely associated with fasting insulin concentration. The multivariate adjusted geometric mean for women in the lowest quartile of magnesium intake was 11.0 μU/mL and 9.3 μU/mL among those in the highest quartile of magnesium intake (p for trend = 0.04). The inverse association remained when we considered magnesium from only food sources. Conclusion: Higher magnesium intake is associated with lower fasting insulin concentrations among women without diabetes. Because lower fasting insulin concentrations generally reflect greater insulin sensitivity, these findings provide a mechanism through which higher dietary magnesium intake may reduce the risk of developing type 2 diabetes mellitus.