Bone mineral density and hypertension prevalence in postmenopausal women: results from the Third National Health and Nutrition Examination Survey

PURPOSE: We sought to corroborate a reported association of hypertension with bone mineral density (BMD) in postmenopausal women. METHODS: Data are from a nationally representative sample of 2738 women aged 50 years and older from the Third National Health and Nutrition Examination Survey. Total proximal femoral bone mineral density was measured by using dual-energy x-ray absorptiometry. Hypertension is defined as blood pressure of 140/90 mm Hg or greater or recent blood pressure medication use. RESULTS: Compared with the fourth quartile of BMD, age- and race-adjusted relative odds of hypertension were decreased in the first quartile (odds ratio [OR], 0.50; 95% confidence interval [CI], 0.38-0.67; p < 0.01). However, the association was diminished and no longer significant after adjusting for body mass index (OR, 0.96; 95% CI, 0.69-1.36; p = 0.83) and additional risk factors in multivariate models (OR, 0.92; 95% CI, 0.65-1.30; p = 0.62). CONCLUSIONS: No association between hypertension and BMD was observed after controlling for body mass index and other confounders.     

Bone mineral density and verbal memory impairment: Third National Health and Nutrition Examination Survey.

Previous studies have examined the relation of endogenous estrogen levels or estrogen replacement therapy to the risk of poor cognitive function, but results have been inconclusive. Bone mineral density has been proposed as a marker for cumulative estrogen exposure. The authors studied the relation of bone mineral density to the prevalence of verbal memory impairment among 4,304 elderly subjects in the Third National Health and Nutrition Examination Survey (1988-1994). Bone mineral density was measured in five regions of the proximal femur with dual-energy x-ray absorptiometry. Verbal memory was assessed using delayed recall of a three-item word list and a six-item story. Verbal memory impairment was defined as a combined score of <4. The prevalence of verbal memory impairment for each increasing bone mineral density quintile at the femoral neck was 8.35, 5.74, 5.22, 5.00, and 3.38% in women and 11.54, 7.27, 8.47, 6.29, and 5.89% in men, respectively. With adjustment for age, sex, and other covariates, the prevalence ratios of verbal memory impairment for each increased bone mineral density quintile were 1.00, 0.64, 0.65, 0.55, and 0.44, respectively (p for trend < 0.001). These results suggest that bone mineral density in the elderly is associated with verbal memory impairment. The mechanisms underlying this relation are not understood, but cumulative exposure to estrogen may play a role.     

Frequency of attendance at religious services, overweight, and obesity in American women and men: the Third National Health and Nutrition Examination Survey

PURPOSE: Few data have been published on the association of overweight and obesity and indices of religiousness, a putative protective factor for cardiovascular morbidity and mortality, in representative samples of multiethnic total populations. METHODS: To test the hypothesis that frequency of attendance at religious services is unrelated to the prevalence of overweight and obesity, the following data from American men and women aged 20 years and older (N = 16,657) in a cross-sectional survey of a large national sample, the Third National Health and Nutrition Examination Survey, were analyzed: self-reported frequency of attendance at religious services, cigarette smoking, health status, sociodemographic variables, and measured body mass index (BMI). RESULTS: In persons 20 years and older, 58% of frequent attenders (> or = 52 times/y) and 53% of others were overweight or obese (BMI > or = 25 kg/m2). After stratifying to eliminate interactions in a logistic regression model and controlling for sociodemographics, smoking, and health status, no significant association was seen in European-American women overall. In all others, the significant positive associations of frequency of attendance and overweight could be explained by these other variables (fully adjusted odds ratio, 1.16; 95% confidence interval, 0.98-1.36; p = 0.08). The same was true for obesity (BMI > or = 30 kg/m2). CONCLUSION: In a national sample of the US population, the prevalence of overweight or obesity is greater in self-reported frequent attenders of religious services than in others, but the association was explained by controlling for multiple sociodemographic and health variables.     

Frequency of attendance at religious services and cigarette smoking in American women and men: the Third National Health and Nutrition Examination Survey

BACKGROUND: Data are lacking from representative samples of total populations and Hispanic Americans on the association of cigarette smoking and religiousness/spirituality, a protective factor for mortality, and on the validity of self-reported smoking data for religious research. METHODS: The Third National Health and Nutrition Examination Survey (NHANES III) included 18,774 persons aged 20 years and over with complete data on self-reported frequency of attendance at religious services, and cigarette smoking. RESULTS: After stratifying by age, gender, and ethnic group, and adjusting for age, education, region, and health status, infrequent attenders (<24 times/year) were much more likely to be smokers than frequent attenders; odds ratios (95% confidence limits) ranged from 1.74 (1.45-2.10) to 3.06 (1.86-5.03). Among current smokers, frequent attenders smoked an average of 1-5 fewer cigarettes per day. Using serum cotinine > or =14 ng/mL as the gold standard for current smoking, under-reporting of smoking did not vary appreciably with frequency of attendance: false negative percentage for never smokers 3.1% in frequent attenders, 4.2% in others. CONCLUSIONS: Greater frequency of attendance at religious services was associated with lower smoking prevalence by self-report or serum cotinine in a national, multi-ethnic sample.     

Vitamin D status is associated with bone mineral density in adolescents: Findings from the Korea National Health and Nutrition Examination Survey

Vitamin D is a factor that regulates calcium and bone metabolism. However, the clinical effect of vitamin D on bone mineral density (BMD) remains controversial. We hypothesized that sufficient vitamin D is required to maintain optimal BMD in adolescents. Based on the Korea National Health and Nutritional Examination Survey, data of 1063 adolescents aged 12 to 18 years were analyzed. The association of vitamin D status and other variables, such as body mass index (BMI), calcium intake, physical activity, lean mass, and fat mass, with BMD Z-scores in the lumbar spine, whole body, total femur, and femur neck were examined. We defined vitamin D deficiency as < 12 ng/mL, vitamin D insufficiency as 12 to 20 ng/mL, and sufficiency as > 20 ng/mL according to the 25-hydroxyvitamin D (25-OHD) level. The mean 25-OHD concentration of subjects was below normal, at 16.28 ng/mL. Subjects with vitamin D deficiency, insufficiency, and sufficiency comprised 20.5%, 58.6%, and 20.9% of all subjects, respectively. The vitamin D sufficient group had higher BMD Z-scores compared to the insufficient group, and the insufficient group had higher BMD Z-scores compared to the deficient group. In linear regression analysis, 25-OHD level, BMI, calcium intake, physical activity, lean mass, and fat mass were positively associated with BMD Z-scores. 25-OHD level was positively associated with BMD Z-scores, even after adjusting for other factors. This study suggests that vitamin D status is positively associated with BMD in adolescents; therefore, maintaining sufficient vitamin D levels during adolescence is crucial to prevent low BMD.     

Lipids and pulmonary function in the Third National Health and Nutrition Examination Survey

Studies considering the association between total cholesterol and noncardiovascular mortality, particularly from respiratory disease, yield inconclusive findings. To explore this question, the relation of lipids to pulmonary function, specifically forced expiratory volume in 1 second (FEV(1)), was investigated in the Third National Health and Nutrition Examination Survey. Conducted in the United States in 1988-1994 among adults aged > or =17 years, this survey measured serum lipids, FEV(1), and confounding factors including smoking and antioxidants. Multiple linear regression analysis explored the relation of FEV(1)/height(2) to low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, and their respective apolipoproteins (apo) B and A-I. A standard deviation increase in HDL cholesterol or apo A-I was associated with an FEV(1) increase of 43 ml (95% confidence interval (CI): 30, 56) or 29 ml (95% CI: 11, 47), respectively, for an average-height adult. A standard deviation increase in LDL cholesterol or apo B was associated with an FEV(1) decrease of -24 ml (95% CI: -43, -5) or -53 ml (95% CI: -74, -32), respectively, adjusted for serum antioxidant status. The lipid subfractions were differentially associated with FEV(1) consistent with the possibility that LDL cholesterol contributes to endogenous oxidative burden while HDL cholesterol attenuates inflammatory tissue damage. Whether these associations are causal remains to be determined.     

Low-serum carotenoid concentrations and carotenoid interactions predict mortality in US adults: the Third National Health and Nutrition Examination Survey

Evidence regarding the health benefits of carotenoids is controversial. Effects of serum carotenoids and their interactions on mortality have not been examined in a representative sample of US adults. The objective was to examine whether serum carotenoid concentrations predict mortality among US adults. The study consisted of adults aged ≥20 years enrolled in the Third National Health and Nutrition Examination Survey, 1988 to 1994, with measured serum carotenoids and mortality follow-up through 2006 (N = 13 293). Outcomes were all-cause, cardiovascular disease, and cancer mortality. In adjusted Cox proportional hazards models, participants in the lowest total carotenoid quartile (<1.01 μmol/L) had significantly higher all-cause mortality (mortality rate ratio, 1.38; 95% confidence interval, 1.15-1.65; P = .005) than those in the highest total carotenoid quartile (>1.75 μmol/L). For α-carotene, the highest quartile (>0.11 μmol/L) had the lowest all-cause mortality rates (P < .001). For lycopene, the middle 2 quartiles (0.29-0.58 μmol/L) had the lowest all-cause mortality rates (P = .047). Analyses with continuous carotenoids confirmed associations of serum total carotenoids, α-carotene, and lycopene with all-cause mortality (P < .001). In a random survival forest analysis, very low lycopene was the carotenoid most strongly predictive of all-cause mortality, followed by very low total carotenoids. α-Carotene/β-cryptoxanthin, α-carotene/lutein+zeaxanthin and lycopene/lutein+zeaxanthin interactions were significantly related to all-cause mortality (P < .05). Low α-carotene was the only carotenoid associated with cardiovascular disease mortality (P = .002). No carotenoids were significantly associated with cancer mortality. Very low serum total carotenoid, α-carotene, and lycopene concentrations may be risk factors for mortality, but carotenoids show interaction effects on mortality. Interventions of balanced carotenoid combinations are needed for confirmation.     

Socioeconomic status and type 2 diabetes in African American and non-Hispanic white women and men: evidence from the Third National Health and Nutrition Examination Survey

OBJECTIVES: This study examined the associations of poverty income ratio (PIR), education, and occupational status with type 2 diabetes prevalence among African American and non-Hispanic White (White) women and men aged 40 to 74 years. METHODS: We analyzed cross-sectional data from the Third National Health and Nutrition Examination Survey, controlling for age and examination-related variables. RESULTS: Among African American women, there was a strong, graded association between PIR and diabetes, which remained significant after other risk factors were adjusted for. All 3 variables were significantly associated with diabetes among White women. Among White men, only PIR was significantly associated with diabetes. Controlling for risk factors substantially attenuated these associations among White women. There were no significant associations for African American men. CONCLUSIONS: Socioeconomic status is associated with type 2 diabetes prevalence among women, but not consistently among men. Diabetes prevalence is more strongly associated with PIR than with education or occupational status. These associations are largely independent of other risk factors, especially among African American women. Economic resources should be addressed in efforts to explain and reverse the increasing prevalence of diabetes in the United States.     

Homocysteine and blood pressure in the Third National Health and Nutrition Examination Survey, 1988-1994

Studies suggest that homocysteine may elevate blood pressure and increase the risk of hypertension. The association of homocysteine with blood pressure and with the risk of hypertension was investigated using cross-sectional data from the Third National Health and Nutrition Examination Survey (1998-1994). Homocysteine had an independent positive association with blood pressure after adjusting for cardiovascular risk factors. A 1 standard deviation ( approximately 5 micro mol/liter) increase in homocysteine was associated with increases in diastolic and systolic blood pressure of 0.5 and 0.7 mmHg, respectively, in men and of 0.7 and 1.2 mmHg in women. Similarly, higher levels of homocysteine were associated with an increased risk of hypertension. In a comparison of the highest and lowest quintiles of homocysteine, women had a threefold increase in the risk of hypertension (95% confidence interval (CI): 1.7, 5.4), and men had a twofold increase (95% CI: 0.7, 5.1). In light of the homocysteine-blood pressure association, the association of homocysteine with prevalent cardiovascular disease was examined with and without adjusting for blood pressure. The results support a mediating role for blood pressure in women and suggest that the full effect of homocysteine on cardiovascular risk may be underestimated when blood pressure is adjusted.     

Total homocysteine and estrogen status indicators in the Third National Health and Nutrition Examination Survey

The possibility that estrogen status modulates total homocysteine concentration, a risk factor for vascular occlusion, was examined in a representative sample of the US population, the Third National Health and Nutrition Examination Survey (phase 2), 1991-1994. The geometric mean serum total homocysteine concentration was compared among population subgroups differing on inferred estrogen status, after adjusting for potential confounding by age, race-ethnicity, smoking, and the serum concentration of creatinine, folate, and vitamin B-12. Premenopausal women aged 17-54 years had a lower mean serum total homocysteine concentration (8.1 micromol/liter, 95% confidence interval (CI): 7.9, 8.2) than men in the same age range (8.9 micromol/liter, 95% CI: 8.6, 9.3). In the age range 17-44 years, pregnant women (6.0 micromol/liter, 95% CI: 5.4, 6.8), but not oral contraceptive users (7.9 micromol/liter, 95% CI: 7.6, 8.2), had a lower mean serum total homocysteine concentration than nonpregnant, non-oral-contraceptive-using women (8.1 micromol/liter, 95% CI: 7.9, 8.2). The mean serum total homocysteine concentration of estrogen-using women aged > or = 55 years (9.5 micromol/liter, 95% CI: 8.9, 10.1) was significantly decreased relative to nonestrogen users (10.7 micromol/liter, 95% CI: 10.3, 11.1) and men (10.4 micromol/liter, 95% CI: 9.8, 11.0) in the same age range. These findings suggest that higher estrogen status is associated with a decreased mean serum total homocysteine concentration, independent of nutritional status and muscle mass, and that estrogen may explain the previously reported male-female difference in total homocysteine concentration.     

Excess type 2 diabetes in African-American women and men aged 40-74 and socioeconomic status: evidence from the Third National Health and Nutrition Examination Survey

OBJECTIVE: To examine whether socioeconomic status (SES) explains differences in the prevalence of type 2 diabetes between African-American and non-Hispanic white women and men. DESIGN: Cross sectional study of diabetes prevalence, SES, and other risk factors ascertained by physical examination and interview. SETTING: Interviews were conducted in subjects' homes; physical examinations were conducted in mobile examination centres. PARTICIPANTS: 961 African-American women, 1641 non-Hispanic white women, 839 African-American men and 1537 non-Hispanic white men, aged 40 to 74 years, examined in the Third National Health and Nutrition Examination Survey (NHANES III), a representative sample of the non-institutionalised civilian population of the United States, 1988-1994. MAIN RESULTS: Among women, African-American race/ethnicity was associated with an age adjusted odds ratio of 1.76 (95% confidence intervals 1.21, 2.57), which was reduced to 1.42 (95% confidence intervals 0.95, 2.13) when poverty income ratio was controlled. Controlling for education or occupational status had minimal effects on this association. When other risk factors were controlled, race/ethnicity was not significantly associated with type 2 diabetes prevalence. Among men, the age adjusted odds ratio associated with African-American race/ethnicity was 1.43 (95% confidence intervals 1.03, 1.99). Controlling for SES variables only modestly affected the odds ratio for African/American race/ethnicity among men, while adjusting for other risk factors increased the racial/ethnic differences. CONCLUSIONS: Economic disadvantage may explain much of the excess prevalence of type 2 diabetes among African-American women, but not among men.     

Differences in energy, nutrient, and food intakes in a US sample of Mexican-American women and men: findings from the Third National Health and Nutrition Examination Survey, 1988-1994

As Mexican-American women and men migrate to the United States and/or become more acculturated, their diets may become less healthy, increasing their risk of cardiovascular disease. Data from the Third National Health and Nutrition Examination Survey (1988-1994) were used to compare whether energy, nutrient, and food intakes differed among three groups of Mexican-American women (n = 1,449) and men (n = 1,404) aged 25-64 years: those born in Mexico, those born in the United States whose primary language was Spanish, and those born in the United States whose primary language was English. Percentages of persons who met the national dietary guidelines for fat, fiber, and potassium and the recommended intakes of vitamins and minerals associated with cardiovascular disease were also compared. In general, Mexican Americans born in Mexico consumed significantly less fat and significantly more fiber; vitamins A, C, E, and B6; and folate, calcium, potassium, and magnesium than did those born in the United States, regardless of language spoken. More women and men born in Mexico met the dietary guidelines or recommended nutrient intakes than those born in the United States. The heart-healthy diets of women and men born in Mexico should be encouraged among all Mexican Americans living in the United States, especially given the increasing levels of obesity and diabetes among this rapidly growing group of Americans.     

Correlates of serum lutein + zeaxanthin: findings from the Third National Health and Nutrition Examination Survey

The determinants of blood levels of carotenoids were previously investigated in small or select samples. The relations of serum lutein + zeaxanthin to possible diet, lifestyle, and physiological determinants in 7059 participants of the Third National Health and Nutrition Examination Survey (1988-1994), > or = 40 y old, were examined. In a fully adjusted, multiple linear regression model, lower serum lutein + zeaxanthin was significantly associated with smoking, heavy drinking, being white, female, or not being physically active, having lower dietary lutein + zeaxanthin, higher fat-free mass, a higher percentage of fat mass, a higher waist-hip ratio, lower serum cholesterol, a higher white blood cell count, and high levels of C-reactive protein (P < 0.05). The model explained 24% of the variation present in serum lutein + zeaxanthin for the current sample. The correlation between dietary and serum lutein + zeaxanthin was 0.17 and increased to 0.18 after adjusting for the effects of given covariates. Each 10% increase in dietary lutein + zeaxanthin was associated with a 1% increase in serum conditional on other terms in the model. Many factors that influence the level of serum lutein + zeaxanthin remain unknown.     

Association of metabolic syndrome and insulin resistance with congestive heart failure: findings from the Third National Health and Nutrition Examination Survey

OBJECTIVE: Congestive heart failure (CHF) has been associated with insulin resistance, but few studies have examined its relationship with metabolic syndrome (MetS). Little is known about whether insulin resistance explains the association between MetS and CHF. DESIGN: Population-based, cross-sectional surveys. SETTING: Third National Health and Nutrition Examination Survey (NHANES III). PARTICIPANTS: Data from 5549 men and non-pregnant women aged > or =40 years in NHANES III were analysed. RESULTS: About 4% of men and 3% of women had CHF between 1988 and 1994 in the US. The age-adjusted prevalence of CHF was significantly higher in African Americans (4.1%), in Mexican Americans (8.5%) and in those of other ethnic origin (6.7%) than in white people (2.5%). People with MetS had nearly twice the likelihood of self-reported CHF (adjusted odds ratio 1.8; 95% confidence interval 1.1 to 3.0) after adjustment for demographic and conventional risk factors such as sex, ethnicity, age, smoking, total cholesterol, left ventricular hypertrophy, and probable or possible myocardial infarction determined by electrocardiography. However, this association was attenuated after further adjustment for insulin resistance as measured by the homoeostasis model assessment (HOMA). >90% of the association between MetS and CHF was explained by the HOMA. CONCLUSIONS: MetS was associated with about a twofold increased likelihood of self-reported CHF and it may serve as a surrogate indicator for the association between insulin resistance and CHF.