Submitted to: University of Southern Mississippi Thesis
Publication Type: Other
Publication Acceptance Date: 8/1/2009
Publication Date: 8/1/2009
Citation: Lartey-Rowser, M. 2009. The relationship between calcium intake, obesity, and cardiovascular disease risk factors:The Jackson Heart Study [dissertation]. University of Southern Mississippi Thesis. 153 p. Interpretive Summary: Cardiovascular disease (CVD) is a significant cause of mortality in U.S. adults, impacting African Americans disproportionately to most ethnic groups. Data suggest that calcium intake may contribute to weight regulation and may be associated with serum lipids and hypertension. This study assessed the relationships between calcium intake and CVD risk factors in African-Americans participating in the Jackson Heart Study. In this study, 5301 free-living African American males and females participated in data collection on factors associated with CVD including weight and height measure, blood samples, blood pressure measures, and dietary assessment using food frequency questionnaires. The results of this study indicate that the relationships between calcium intake and body mass index, total cholesterol, high-density lipoprotein and low-density lipoprotein in African-American adults vary between genders (from being a positive relationship to a negative relationship depending on the factor). In addition, the strength of those relationships may not be clinically meaningful. These findings are very relevant to nutrition educator in that these findings can possibly give insight into the impact of calcium intake on the African American population.
Technical Abstract: Cardiovascular disease (CVD) is a major health risk in the United States. Major indicators of CVD risk include obesity, blood lipids, and blood pressure. Modifiable risk factors associated with CVD include body composition (body mass index and waist circumference), serum lipids, and blood pressure. Data suggest calcium intake may play a role in regulation of weight, serum lipids, and blood pressure. The purpose of this study was to assess realtionships of dietary calcium intake with weight status, and cardiovascular disease risks in African American populations participating in the Jackson Heart Study. The subjects included 4,267 African American adults ages 21-95 years (mean=55.1 +/- 12.6 years) in the Jackson Heart Study. Dependent variables included: body mass index (BMI) calculated from measured height/weight (stadiometer/balance scale), waist circumference (WC;measuring tape),serum lipids, and blood pressure (sphygmomanometer). A 158-item FFQ was used to assess nutrient intake. Statistical analyses included multiple regression analysis and Pearson correlations using SPSS 16.0. There was a significant positive relationship between calcium intake and body composition measures BMI [F (4,3982) = 3.26, p = 0.019,change R**2=.003] and significant inverse relationship between calcium intake and WC [F(4,3982)=2.43,p=0.05, change R**2=.002]. These relationships were also observed in females only when data was analyzed by gender. There were significant inverse relationships between calcium intake and total cholesterol (TC) [F(4,4259=5.46, p=0.266, change R**2=.002] and LDL-cholesterol (LDL) [F(4,4225=3.218 p=0.01, change R**2=.003]. There were also significant inverse correlations between TC and LDL and calcium for males only. There was a significant relationship between calcium intake and HDL-cholesterol [F(4,4259)=13.31, p<0.001, change R**2=.012], direction based on the calcium source. There was a significant positive relationship between total calcium intakes and systolic blood pressure (SBP)[F(4,3986)=4.74,p0.001, change R**2=.004]. There was a significant relationship between calcium intake and diastolic blood pressure (DBP) [F(4,3986)=4.84, p=0.01, change R**2=.005], direction based on the calcium source. There was no association between calcium intake and triglycerides. While significant negative associations were noted between dietary calcium intake and WC,TC,LDL, and SBP for JHS participants, and significant positive associations between dietary calcium and BMI, HDL, and DBP, the magnitude of the relationships was small. This can be related to several factors inlcuding the true predictive power of calcium over CVD risk factor measures (which may be highly multifactoral variables). Data from this study suggests the need for additional research in African American populations on the relationship between calcium intake and BMI, WC, serum lipids, and blood pressure.