The relationship between zinc and copper status and lipid levels in African-Americans.

Studies examining the role of zinc and copper nutriture as risk factors for cardiovascular disease in European Americans have produced conflicting results. This study assessed the associations between zinc and copper status and serum lipid levels in an adult African-American community. A cross-sectional study was conducted on 600 individuals (233 males, 367 females) from 25 to 65 yr of age using a random sampling design in a small city in Alabama. Anthropometric, dietary, and serum zinc, copper, and lipid measurements were made. The mean serum zinc and copper levels and dietary zinc intake were similar to that reported previously for European Americans. There were no significant associations between serum zinc, copper, or zinc/copper ratio and total serum cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), or triglyceride levels. For males, there was a small but significant association between dietary zinc and the total cholesterol/HDL-C ratio (r = -0.17, p = 0.03). Similarly, females taking either zinc supplements or a multivitamin including zinc had higher HDL-C values than nonsupplementing females. Further prospective studies of the relationship between zinc status and lipid levels in African Americans are needed to verify these results.

Increased risk of preterm delivery with elevated maternal alpha-fetoprotein and plasma zinc levels in African-American women.

BACKGROUND: This study evaluated the relationship of maternal serum alpha-fetoprotein (MSAFP) and plasma zinc levels (PZn) to pregnancy outcome. METHODS: The subjects for this investigation consisted of 917 African-American women, who on registration for prenatal care between 7-22 weeks gestational age (GA), had PZn levels determined and also had MSAFP recorded in their charts. RESULTS: MSAFP levels greater than the 90th percentile significantly increased the risk of PTD (adjusted odds ratio or AOR=2.5, 95% C.I.=1.5-4.2) but not of IUGR. There was no significant relationship between maternal PZn level and PTD or IUGR. When subjects were stratified by MSAFP levels, in women with MSAFP greater than the 90th percentile, the AOR for PTD was 4.0 (95% C.I.=1.2-13.5) for women with PZn levels greater than the median vs. those with PZn equal to or less than the median. In women with MSAFP equal to or less than the 90th percentile, there was no such difference. Multiple regression analyses, using GA at birth as the dependent variable, indicated an interaction between MSAFP and PZn levels. CONCLUSION: In this population, the adverse pregnancy outcome associated with elevated MSAFP was seen only in women with PZn levels greater than the median. The reason for this association is not currently apparent.

Determinants of zinc intake in low-income black and white pregnant women.

A prospective study was conducted to evaluate and compare the determinants of dietary zinc intake in black and white low-income pregnant women. The study population consisted of 1298 low-income women (70% Black, 30% White) who received prenatal care at University Hospital at the University of Alabama in Birmingham from 1985 to 1989. Various maternal characteristics were evaluated at the first prenatal visit. Two 24 h recalls were obtained at 18 and 30 wk of gestation to calculate the intakes of dietary zinc and other nutrients. Student's t test, chi2, Pearson correlation coefficients, and multiple regression analyses were used to compare and evaluate the determinants of zinc and other nutrient intakes in Black and White subjects. The mean prepregnancy body mass index and the mean intake of zinc, energy, and all the other nutrients except calcium were significantly higher in Black than in White subjects. There was a significant correlation between zinc and energy intake (r = 0.69, p = 0.001). Age, marital status, parity, socioeconomic status, smoking, and alcohol intake were not significant predictors of zinc or other nutrient intakes. After adjusting for energy intake, race was the only significant predictor of dietary zinc intake. Race and energy intake explained 24% of the variation in zinc intake. Results of this study indicate that after adjusting for other covariates, race and energy intakes are the only predictors of zinc intake in low-income pregnant women.

John Henryism, gender, and arterial blood pressure in an African American community.

OBJECTIVE: To examine the interaction between gender and John Henryism in relationship to arterial blood pressure in an African American community in the Southern United States. It was hypothesized that, within this specific social and cultural context, John Henryism would be associated with blood pressure differently for men and women. METHODS: A cross-sectional survey of 600 persons, aged 25 to 65, was conducted in the African American community of a small Southern city. John Henryism was assessed using the 12-item John Henryism Scale for Active Coping. Blood pressure was assessed by conventional methods. RESULTS: The interaction effect between gender and John Henryism was assessed as a cross-product term in ordinary least squares regression analysis using arterial blood pressure as the dependent variable, and with logistic regression using hypertension as the dependent variable. This interaction effect was significant (p < .05) in relation to systolic blood pressure and hypertension, with the effect evident (p < .07) in relation to diastolic blood pressure. For men, as John Henryism increases, blood pressure and the risk of hypertension increases. For women, as John Henryism increases, blood pressure and the risk of hypertension decreases. CONCLUSIONS: The association of the behavioral disposition of John Henryism with blood pressure is dependent on the gender of the individual. Men and women face differing cultural expectations and social structural constraints in this community. The sociocultural context modifies the meaning of the behavioral disposition, and hence its effects.

Culture, socioeconomic status, and coronary heart disease risk factors in an African American community.

In this paper, cultural influences are examined in the relationship between socioeconomic status and health. Cultural definitions of material lifestyles are investigated as a correlate of disease risk in an African American community in the rural South. A new technique--called "cultural consensus analysis"--is used to test for a cultural model of lifestyles indicative of success. Survey data are then used to operationalize the degree to which individuals adhere in their own behavior to that cultural model; this measure is referred to as "cultural consonance in lifestyle." Cultural consonance in lifestyle is more strongly associated with hypertension and smoking (but not serum lipids) than are conventional measures of socioeconomic status (occupation, income, and education). These results suggest that the extent to which individuals are unable to live in accordance with cultural norms regarding lifestyles may contribute to the risk of coronary heart disease in the African American community.

Plasma and erythrocyte zinc concentrations and their relationship to dietary zinc intake and zinc supplementation during pregnancy in low-income African-American women.

OBJECTIVE: To evaluate the effects of usual dietary intake of zinc and of zinc supplementation during pregnancy on plasma and erythrocyte zinc concentrations. DESIGN: A randomized, double-blind, placebo-controlled trial. SUBJECTS: Low-income African-American women (n = 580) assigned randomly to groups at 19 weeks of gestation. INTERVENTION: A daily dose of zinc (25 mg) or a placebo until delivery. MAIN OUTCOME MEASURES: Plasma, erythrocyte, and dietary zinc levels. STATISTICAL ANALYSES: Multiple regression and repeated measures analysis of variance. RESULTS: In both the placebo and the supplemented groups, when all subjects were grouped by usual dietary zinc intake above or below the median (12 mg/day), results were the same: Women with high dietary zinc intake had higher erythrocyte zinc levels at the time of randomization and at all subsequent measurements during pregnancy than those who had low dietary zinc intake (P < or = .06; difference not significant for zinc-supplemented group); no difference was observed for plasma zinc levels. On the other hand, when the subjects were stratified at the median by total daily zinc intake (usual dietary zinc + 25 mg zinc supplement) during pregnancy, a significant difference in plasma zinc levels (P < .005) was found between women with high total zinc intake (mean = 38 mg/day) and low total intake (mean = 13 mg/day) at 26, 32, and 38 weeks of gestation; however, no such differences were found in erythrocyte zinc levels. APPLICATIONS: These results should help dietitians and other health professionals better understand the expected changes in plasma and erythrocyte zinc levels during pregnancy, and the relationship between dietary and supplemental zinc and zinc nutriture.

Plasma alkaline phosphatase and pregnancy outcome.

The objective was to determine the relationship between plasma alkaline phosphatase (AP) activity and birthweight (BWT) and preterm delivery (PTD). Five hundred eighty African-American women had plasma AP activities measured at various gestational ages (GA) with the results compared to a number of pregnancy outcomes. Plasma AP activity rose linearly during pregnancy from a mean of 39 U/L at 19 weeks to 130 U/L at delivery. In individual women, AP activities were consistently high or low as confirmed by correlation coefficients in adjacent time periods ranging from 0.63 to 0.87. AP at 19 weeks was not significantly associated with any outcome measure. However, at 26 weeks, AP in the highest quartile was associated with a 15.0% incidence of PTD < 37 weeks compared to 6.8% in the lower three quartiles (P = .004). For PTD < or = 32 weeks, the difference of PTD was 6.8 vs. 1.6% (P < .003). When women in the highest quartile of increase in AP from 19 to 26 weeks were compared to those in the lower quartiles, the rate of PTD < 37 weeks was 15.2 vs. 6.4% (P = .002), and the rate of PTD < or = 32 weeks was 6.1 vs. 1.7%, (P = .01). The mean BWT for the highest vs. the lower three quartiles in rate of increase was 3,058 vs. 3,288 g (P = .0005) and the mean GA was 38.1 vs. 39.2 weeks (P = .0001). Regression analyses adjusting for multiple confounders confirmed the association between high AP at 26 weeks and PTD < 37 weeks [OR (95% C.I.), 2.4 (1.2-4.8)] and PTD < or = 32 weeks [OR (95% C.I.), 3.7 (1.2-11.7)]. Similar results were found among women with a large increase in AP between 19 and 26 weeks. From these results we conclude that high or increasing AP activity at 26 weeks, but not 19 weeks, was significantly associated with subsequent PTD and a lower BWT.

The relationship between maternal characteristics and fetal and neonatal anthropometric measurements in women delivering at term: a summary.

BACKGROUND: We wanted to determine the relationship between a number of maternal characteristics and various fetal and neonatal anthropometric measurements determined by ultrasound and at birth. METHODS: A total of 1205 term singleton maternal-infant pairs were studied. Various ultrasound measurements obtained at 18, 24, 30 and 36 weeks' gestation and neonatal anthropometric measurements obtained at birth were studied in relationship to various maternal characteristics using univariate and multivariate techniques. RESULTS: Black race, female sex, cigarette smoking, drug use, having a previous low birthweight infant, maternal hypertension and being short or thin or failing to gain weight each resulted in a birthweight decrease of 100 to 300 g. The effect of each of these characteristics on each ultrasound measurement, the timing of the effect, and its ultimate effect on neonatal anthropometric measurements are described. CONCLUSION: The data presented in this paper provide a more complete understanding of the relationship between maternal characteristics, infant sex, and various fetal ultrasound and neonatal measurements.

The relationship between maternal dietary intake and infant birthweight.

BACKGROUND: Zinc and folate are important for fetal growth. However, the relationship between the dietary intake of these nutrients and pregnancy outcome is not settled. METHODS: A prospective study was conducted to ascertain the relationship between maternal dietary zinc and folate intake (n = 1398), serum zinc and folate levels (n = 289), and infant birthweight. Twenty-four hour recalls were used to measure energy, zinc, folate and other nutrient intakes at 18 and 30 weeks of gestation. Subjects in the study were offered daily folic acid (1.0 mg) and iron (60 mg as ferrous sulfate) at enrollment. RESULTS: Maternal zinc nutriture as assessed by serum and dietary intake was not associated with birthweight or length of gestation. There was a small but significant positive association between maternal folate intake and adjusted infant birthweight (beta = 0.05, p = 0.03). The indirect measures of maternal nutritional status including maternal pre-pregnancy weight (beta = 8.0, p = 0.0001) and weight gain during pregnancy (beta = 18.1, p = 0.0001) were stronger predictors of adjusted infant birthweight as compared to energy intake and intake of zinc and folate. An increase of 320, 290, and 48 g in infant birthweight was associated with the 90th-10th percentile difference for pre-pregnancy weight, weight gain during pregnancy, and folate intake respectively. CONCLUSION: These results indicate that pre-pregnancy weight and weight gain during pregnancy are both strong predictors of infant birthweight. Folate intake, although significantly associated with birthweight, was a weak predictor while maternal intake of zinc and other nutrients was not associated with birthweight.

Plasma ferritin and pregnancy outcome.

OBJECTIVE: Plasma ferritin is considered the best measure of total body iron, with low levels diagnostic of iron deficiency. High levels have been associated with inflammation and infection. We determined the relationship between plasma ferritin, birth weight, and preterm delivery. STUDY DESIGN: Plasma ferritin and hematocrit values were measured at 19, 26, and 36 weeks' gestational age and correlated with birth weight and preterm delivery (< or = 32 and < 37 weeks) in 580 indigent black women. RESULTS: Hematocrit levels measured at any gestational age did not correlate significantly with birth weight or preterm delivery. Regardless of the gestational age of sampling, ferritin levels in the lowest quartile did not correlate significantly with subsequent preterm delivery. However, at 26 weeks, compared with the three lower quartiles, ferritin levels in the highest quartile were significantly associated with preterm delivery < or = 32 weeks, 6.5% versus 2.3% (p = 0.02), with preterm delivery < 37 weeks, 14% versus 8% (p = 0.04), and with birth weight < 1500 gm, 6.5% versus 2.0% (p = 0.01). Plasma ferritin levels in the highest quartile at 19, 26, and 36 weeks were associated with birth weight < or = 2500 gm, 14% versus 8% (p = 0.03), 12% versus 7% (p = 0.05), and 10% versus 2% (p = 0.0001), respectively, compared with the lower quartiles. Ferritin levels in the highest quartile were always associated with a lower mean birth weight than were those in the lower three quartiles: 19 weeks, 2999 gm versus 3225 gm, (p = 0.002); 26 weeks, 3065 gm versus 3257 gm, (p = 0.005); and 36 weeks, 3182 gm versus 3323 gm, (p = 0.009). Regression analyses controlling for multiple potential confounders confirmed that at 26 weeks ferritin levels in the highest quartile had an odds ratio and 95% confidence interval for preterm birth < 37 weeks of 2.0 (1.1 to 3.8), preterm delivery < or = 32 weeks of 2.7 (0.99 to 7.6), birth weight < or = 1500 gm of 3.9 (1.2 to 12.2), and birth weight < or = 2500 gm of 2.0 (1.0 to 4.0) compared with the three lower ferritin quartiles. CONCLUSION: High, but not low, plasma ferritin levels, especially at 26 weeks, were strongly associated with subsequent preterm delivery and birth weight.

Factors influencing plasma zinc levels in low-income pregnant women.

Plasma zinc (Zn) concentrations were measured in 4376 indigent women (86% African-American), at at mean (+/- SD) gestational age of 15 (+/- 7.8) wk to determine the relationship between various maternal characteristics and plasma Zn levels during pregnancy. Mean Plasma An levels were lower in African-American women than in Caucasian women, in multiparous women than in primiparous women, and in women with body weight > 69.9 kg than in those with body weight < or = 69.9 kg (p < or = 0.001 for each comparison). There were no significant differences related to maternal age, marital status, education, or smoking habit. Multiple regression analysis, including maternal prepregnancy weight, race, age, parity, smoking habit, education, and marital status indicated that race, parity, and pregnancy weight were significantly associated with maternal plasma Zn levels, adjusted for gestational age. Maternal race was the best predictor of plasma Zn concentrations among the population of pregnant women studied A significant proportion of variance in maternal plasma Zn levels. remained unexplained after taking into account various maternal characteristics. The reasons for lower plasma Zn levels in African-American women, compared to Caucasian women, during pregnancy are unknown.

The effect of zinc supplementation on pregnancy outcome.

OBJECTIVE: To evaluate whether zinc supplementation during pregnancy is associated with an increase in birth weight. DESIGN: A randomized double-blind placebo-controlled trial. SETTING: Outpatient clinic and delivery service at the University of Alabama at Birmingham. PATIENTS: Five hundred eighty medically indigent but otherwise healthy African-American pregnant women with plasma zinc levels below the median at enrollment in prenatal care, randomized at 19 weeks' gestational age. Women were subdivided by the population median body mass index of 26 kg/m2 into two groups for additional analyses. INTERVENTION: Women who were taking a non-zinc-containing prenatal multivitamin/mineral tablet were randomized to receive either a daily dose of 25 mg of zinc or a placebo until delivery. MAIN OUTCOME MEASURES: Birth weight, gestational age at birth, and head circumference at birth. RESULTS: In all women, infants in the zinc supplement group had a significantly greater birth weight (126 g, P = .03) and head circumference (0.4 cm, P = .02) than infants in the placebo group. In women with a body mass index less than 26 kg/m2, zinc supplementation was associated with a 248-g higher infant birth weight (P = .005) and a 0.7-cm larger infant head circumference (P = .007). Plasma zinc concentrations were significantly higher in the zinc supplement group. CONCLUSIONS: Daily zinc supplementation in women with relatively low plasma zinc concentrations in early pregnancy is associated with greater infant birth weights and head circumferences, with the effect occurring predominantly in women with a body mass index less than 26 kg/m2.

The relationship between maternal and neonatal anthropometric measurements in term newborns.

OBJECTIVE: To determine whether measures of maternal lean mass, fat reserves, or a combination of both best predict the various measures of newborn size at birth. METHODS: The population consisted of 1205 multiparous, predominantly black women at high risk for fetal growth retardation, who delivered at term at the University of Alabama at Birmingham. Maternal body mass index (BMI) was calculated using the reported pre-pregnancy weight. Maternal anthropometric measurements taken at mid-pregnancy included skinfold thicknesses, lean body mass, and mid-arm, calf, and wrist circumferences. Weight and 11 other neonatal measurements were made within 24 hours of birth and related to various maternal anthropometric measurements. RESULTS: Reported maternal pre-pregnancy weight was the best predictor of all neonatal size measures except for the neonatal skinfold thicknesses, which were better predicted by the pre-pregnancy BMI. For example, the range between the tenth and 90th percentiles of maternal pre-pregnancy weight (46.3-86.4 kg) was associated with 295 g birth weight compared to only 188 g birth weight for a measure of lean body mass. CONCLUSION: Most maternal anthropometric measurements were significantly associated with most neonatal measurements. However, for nearly every neonatal measurement considered, the maternal pre-pregnancy weight was the best predictor.

The relationship between maternal skinfold thickness, smoking and birthweight in black and white women.

A prospective study was conducted in a sample of 1491 multiparous women to ascertain whether the relationship between maternal tricep skinfold thickness and infant birthweight is modified by smoking status and whether the relationship is different in white and black infants. Maternal tricep skinfold thickness measured at midpregnancy was a significant predictor of infant birthweight in both white and black infants after adjusting for gestational age at birth, maternal height, maternal age, parity, alcohol consumption and sex of the infant. However, maternal tricep skinfold thickness was a better predictor of birthweight in smokers compared with nonsmokers. Both white and black women with tricep skinfold thickness below the sample mean had lower infant birthweight than women with tricep skinfold at or above the mean, after adjusting for gestational age at birth, but the difference was greater in smokers (198 g for white and 221 g for black infants) than in nonsmokers (124 g for white and 221 g for black infants) than in nonsmokers maternal subcutaneous fat measured by tricep skinfold thickness has a greater effect on infant birthweight in smokers compared with nonsmokers, with similar effects in white and black infants.

The relationship between maternal serum zinc levels during pregnancy and birthweight.

A retrospective follow-up study to ascertain the relationship between the level of serum zinc and its rate of change during gestation and birthweight was conducted in 476 women of lower socioeconomic status. Serum zinc concentrations measured at approximately 16 (early) and 32 weeks (later) in gestation were both found to be significant predictors of birthweight. Even after controlling for gestational age at birth and other determinants of birthweight, for each microgram/dl increase in serum zinc early and later in pregnancy, birthweight increased by 5.8 and 8.6 g, respectively. Furthermore, after adjustment for initial zinc levels both the total change (beta = -7.0, P = 0.0007) and the rate of change (beta = -60.8, P = 0.007) in serum zinc during pregnancy were inversely associated with birthweight, i.e., the larger the fall in serum zinc during pregnancy, the smaller the infant. Low serum zinc level (less than 60 micrograms/dl) late in pregnancy was associated with greater than a five-fold increase in the odds (OR = 5.8, 95% CI = 1.8, 16.4) of giving birth to a low birthweight infant. The results of this study suggest a threshold for maternal serum zinc below which the prevalence of low birthweight increases rapidly.

A positive association between maternal serum zinc concentration and birth weight.

A study was conducted on a cohort of 476 women (364 black, 112 white), who attended the Jefferson County Health Department clinic for their prenatal care, to ascertain the relationship between maternal serum zinc concentration measured early in pregnancy and birth weight. For all subjects maternal serum zinc was significantly related to birth weight after various independent determinants of birth weight were controlled for. The data in this study indicate a threshold for maternal serum zinc concentration below which the prevalence of low birth weight increases significantly. Pregnant women who had serum zinc concentrations in the lowest quartile had significantly higher prevalence of low birth weight than did those mothers who had serum zinc concentrations in the upper three quartiles during pregnancy. These findings suggest that maternal serum zinc concentration measured early in pregnancy could be used to identify those women at higher risk of giving birth to a low-birth-weight infant.