Uterine fibroid incidence and growth in an ultrasound-based, prospective study of young African Americans.

BACKGROUND: Uterine fibroids are common. Symptoms are debilitating for many, leading to high medical and societal costs. Indirect data suggest that compared with white women, African Americans develop fibroids at least 10 years earlier on average, and their higher health burden has been well documented. OBJECTIVE: The objective of the study was to directly measure fibroid incidence and growth in a large, community-based cohort of young African-American women. STUDY DESIGN: This observational, community-based, prospective study enrolled 1693 African-American women, aged 23-35 years with no prior diagnosis of fibroids. Standardized transvaginal ultrasound examinations at enrollment and after approximately 18 months were conducted to identify and measure fibroids ≥0.5 cm in diameter. Fibroid growth (change in natural log volume per 18 months) was analyzed with mixed-model regression (n = 344 fibroids from 251 women whose baseline ultrasound revealed already existing fibroids). RESULTS: Among the 1123 fibroid-free women with follow-up data (88% were followed up), incidence was 9.4% (95% confidence interval, 7.7-11.2) and increased with age (Ptrend < .0001), from 6% (confidence interval, 3-9) for 23-25 year olds to 13% (confidence interval, 9-17) for 32-35 year olds. The chance of any new fibroid development was greater than twice as high for women with existing fibroids compared with women who were fibroid free at baseline (age-adjusted relative risk = 2.3 (confidence interval, 1.7-3.0). The uterine position of most incident fibroids (60%) was intramural corpus. Average fibroid growth was 89% per 18 months (confidence interval, 74-104%) but varied by baseline fibroid size (P < .0001). Fibroids ≥2 cm in diameter had average growth rates well under 100%. In contrast, small fibroids (<1 cm diameter) had an average growth rate of nearly 200% (188%, confidence interval, 145-238%). However, these small fibroids also had a high estimated rate of disappearance (23%). CONCLUSION: This is the first study to directly measure age-specific fibroid incidence with a standardized ultrasound protocol and to measure fibroid growth in a large community-based sample. Findings indicate that very small fibroids are very dynamic in their growth, with rapid growth, but a high chance of loss. Larger fibroids grow more slowly. For example, a 2-cm fibroid is likely to take 4-5 years to double its diameter. Detailed data on fibroid incidence confirm an early onset in African-American women.

The relationship between pregnancy weight gain and glucose tolerance status among black and white women in central North Carolina.

OBJECTIVE: The objective of the study was to examine weight and its relationship to glucose intolerance during pregnancy. STUDY DESIGN: Women were classified into mutually exclusive glucose tolerance groups; impaired glucose tolerance of pregnancy defined as 1 high value on the oral glucose tolerance test, gestational diabetes mellitus as 2 high values, and normal glucose tolerance as a normal value on the universal screen test. Logistic regression was used to examine the relationship between prepregnancy body mass index and weight gain, and glucose tolerance status and predicted probabilities were calculated. RESULTS: Weight gain ratio (observed/expected) was significantly higher for women with gestational diabetes mellitus, compared with women with normal glucose tolerance. The likelihood of developing gestational diabetes mellitus was significantly increased by both prepregnancy overweight (odds ratio 2.2, 95% confidence interval 1.1-4.3) and obese status (odds ratio 3.7, 95% confidence interval 2.2-6.3) but only marginally by weight gain ratio. In contrast, the likelihood of developing impaired glucose tolerance was increased by weight gain ratio for women who started pregnancy overweight. CONCLUSION: Prepregnancy weight was strongly associated with gestational diabetes mellitus, whereas weight gain during pregnancy was associated with impaired glucose tolerance only among overweight women.

The association between impaired glucose tolerance and birth weight among black and white women in central North Carolina.

OBJECTIVE: This study examines the relationship of glucose intolerance during pregnancy to birth weight among black and white participants of the Pregnancy, Infection, and Nutrition Study. RESEARCH DESIGN AND METHODS: This prospective cohort study recruited women from prenatal clinics in central North Carolina at 24-29 weeks' gestation. A 1-h 50-g glucose challenge test (GCT) and 100-g oral glucose tolerance test (OGTT) were conducted. Impaired glucose tolerance (IGT) was defined as one high value on the OGTT, gestational diabetes mellitus (GDM) as two or more high values, and normal glucose tolerance (NGT) was defined as a low or high value on the GCT screen but no high values on the OGTT. Women with known glucose status and birth outcome information were included in this analysis (n = 2055). RESULTS: Black women with IGT had higher rates of both macrosomia (38.5%) and large for gestational age (LGA) (53.9%) compared with white women (10.0% and 13.2%). Black infants' birth weights (3800 g) and prevalence of macrosomia and LGA were significantly higher among mothers with IGT compared with NGT women (birth weight, 3184 g; macrosomia, 7.0%; LGA, 11.6%). In contrast, among white infants, there was no significant increase in birth weight, macrosomia, or LGA associated with the mother's glucose tolerance status. In addition, there was no effect of GDM on birth weight in either group. CONCLUSIONS: This study suggests that, independent of maternal prepregnant weight, there may be significant increased risk of macrosomia among black IGT women but not among white IGT women. Further investigations into factors that may contribute to the observed results are needed.

Effect of macronutrient intake on the development of glucose intolerance during pregnancy.

BACKGROUND: Dietary intake influences glucose tolerance status, yet the relation between macronutrient intake and the development of glucose intolerance during pregnancy has not been adequately examined. OBJECTIVE: We examined the relation between macronutrient intake early in pregnancy and the development of glucose intolerance. DESIGN: Data are from 1698 women in the Pregnancy, Infection, and Nutrition Study. Dietary intake during the second trimester was assessed with a food-frequency questionnaire. Women were classified into 1 of 3 glucose categories: gestational diabetes mellitus (GDM), impaired glucose tolerance (IGT), and normal glucose tolerance. Multivariate logistic regression was used to calculate the relative risk of IGT and GDM, with adjustment for potential confounders. A series of models were specified to test alternate hypotheses about the relation of diet to risk of IGT or GDM. RESULTS: The overall prevalences of IGT and GDM in the cohort were 2.6% and 5.2%, respectively. The addition model showed that adding 100 kcal from carbohydrates to the diet was associated with a 12% decrease in risk of IGT and a 9% decrease in risk of GDM. The substitution model showed that substituting fat for carbohydrates (per each 1% of total calories) resulted in a significant increase in risk of both IGT and GDM [relative risk = 1.1 (95% CI: 1.02, 1.12) and 1.1 (1.02, 1.10), respectively]. Predicted probabilities of IGT and GDM were reduced by one-half with a 10% decrease in dietary fat and a 10% increase in carbohydrate. CONCLUSIONS: This study found an association between increased fat intake and the development of glucose abnormalities in pregnancy.

Within-person variability in urinary phthalate metabolite concentrations: measurements from specimens after long-term frozen storage.

Laboratory studies show that exposure to phthalates during development can cause adverse effects, especially for males. Studies in humans would be facilitated by collection of urine during pregnancy, long-term storage, and measurement of phthalate metabolites at the time that offspring health is assessed. Our aims were to measure urinary phthalate metabolites after long-term freezer storage, to use those measurements to evaluate within-woman variability over 2- and 4-week intervals, and to determine whether the phases of the menstrual cycle affect metabolite levels. Samples were selected from daily first-morning urine specimens collected by 60 women and stored frozen since 1983-1985. Three specimens per woman were selected at approximately 2-week intervals to include both follicular and luteal phase samples. Seven metabolites of five phthalates were measured by mass spectrometry. Statistical analyses were conducted with correlation, mixed model regression, and the Wilcoxon signed rank test. Creatinine-corrected urinary phthalate metabolite concentrations measured in samples after long-term storage tended to have a similar right-skewed distribution, though with somewhat higher concentrations than those reported for recently collected US samples. The concentrations of three metabolites of di(2-ethylhexyl)phthalate in the same specimen were very highly correlated (Pearson r=0.85-0.97). Reproducibility over a 4-week interval was moderate for the metabolites of diethyl phthalate and benzylbutyl phthalate (intraclass correlation coefficients, ICCs, 0.48 and 0.53, respectively), whereas five other metabolites had lower ICCs (0.21-0.37). Menstrual phase was not related to metabolite concentrations. Although the same samples have not been measured both before and after long-term storage, results suggest that the measurement of phthalate metabolites after long-term sample storage yield generally similar distributions and temporal reliability as those reported for recently collected specimens. These findings support the use of stored urine specimens collected during the relevant stage of human pregnancy to investigate the influence of phthalate exposures on later outcomes.

Pesticide exposure and hypertensive disorders during pregnancy.

BACKGROUND: Hypertensive disorders of pregnancy, including pregnancy-induced hypertension (PIH) and preeclampsia (PE), complicate 2-8% of pregnancies. Few studies have examined environmental risk factors in relation to these conditions. OBJECTIVES: Our goal was to examine whether pesticide exposure during pregnancy was associated with hypertensive disorders of pregnancy. METHODS: We analyzed self-reported data from 11,274 wives of farmers enrolled in the Agricultural Health Study (AHS) between 1993 and 1997. Using logistic regression models, we estimated the adjusted odds ratios (AORs) for PIH and PE associated with pesticide-related activities during the first trimester of pregnancy. RESULTS: First-trimester residential and agricultural activities with potential exposure to pesticides were associated with both PIH [residential AOR = 1.27; 95% confidence interval (CI), 1.02-1.60; agricultural AOR = 1.60; 95% CI, 1.05-2.45] and PE (residential AOR = 1.32; 95% CI, 1.02-1.70; agricultural AOR = 2.07; 95% CI, 1.34-3.21). CONCLUSIONS: Exposure to pesticides during pregnancy may increase the risk of hypertensive disorders of pregnancy. Laboratory research may provide insights into relationships between pesticide exposure and hypertensive diseases of pregnancy.

Carbonated beverages and chronic kidney disease.

BACKGROUND: Carbonated beverage consumption has been linked with diabetes, hypertension, and kidney stones, all risk factors for chronic kidney disease. Cola beverages, in particular, contain phosphoric acid and have been associated with urinary changes that promote kidney stones. METHODS: We examined the relationship between carbonated beverages (including cola) and chronic kidney disease, using data from 465 patients with newly diagnosed chronic kidney disease and 467 community controls recruited in North Carolina between 1980 and 1982. RESULTS: Drinking 2 or more colas per day was associated with increased risk of chronic kidney disease (adjusted odds ratio = 2.3; 95% confidence interval = 1.4-3.7). Results were the same for regular colas (2.1; 1.3-3.4) and artificially sweetened colas (2.1; 0.7-2.5). Noncola carbonated beverages were not associated with chronic kidney disease (0.94; 0.4-2.2). CONCLUSIONS: These preliminary results suggest that cola consumption may increase the risk of chronic kidney disease.

Pesticide exposure and self-reported gestational diabetes mellitus in the Agricultural Health Study.

OBJECTIVE: To examine the association between pesticide use during pregnancy and gestational diabetes mellitus (GDM) among wives of licensed pesticide applicators. RESEARCH DESIGN AND METHODS: Using data from the Agricultural Health Study (AHS), we estimated the association between self-reported pesticide-related activities during the first trimester of the most recent pregnancy and GDM among 11,273 women whose pregnancy occurred within 25 years of enrollment. RESULTS: A total of 506 (4.5%) women reported having had GDM. Women who reported agricultural pesticide exposure (mixing or applying pesticides to crops or repairing pesticide application equipment) during pregnancy were more likely to report GDM (odds ratio [OR] 2.2 [95% CI 1.5-3.3]). We saw no association between residential pesticide exposure (applying pesticides in the home and garden during pregnancy) and GDM (1.0 [0.8-1.3]). Among women who reported agricultural exposure during pregnancy, risk of GDM was associated with ever-use of four herbicides (2,4,5-T; 2,4,5-TP; atrazine; or butylate) and three insecticides (diazinon, phorate, or carbofuran). CONCLUSIONS: These findings suggest that activities involving exposure to agricultural pesticides during the first trimester of pregnancy may increase the risk of GDM.