S-44-3: GENDER DIFFERENCE IN THE ASSOCIATION OF DIETARY CALCIUM INTAKE WITH BLOOD PRESSURE: ANALYSIS OF THE NHANES 2017 - 2020

Abstract

Background: Higher dietary calcium intake is associated with lower blood pressure. This association among different genders is unclear. Methods: A cross sectional study utilizing data from the National Health and Nutrition Examination Survey (NHANES) from 2017 to 2018 included participants ≧18 years old. The Association between the quartile of the dietary calcium intake and systolic and diastolic hypertension defined as three average measured systolic blood pressure ≧130 and diastolic blood pressure ≧80 mmHg, respectively was examined by multiple logistic regression. Results: Of 11,137 study participants, the mean ± SD age was 50 ± 19 years old and 51% were female. Up to 35% were White followed by Black, Asian, and other races. Median (interquartile range; IQR) dietary calcium intake of quartile 1 to quartile 4 were 21 (13, 33), 120 (83, 183), 233 (220, 293), and 625 (500, 959) mg/day, respectively. Average systolic blood pressure and diastolic blood pressure were 124 ± 19 and 74 ± 12 mmHg, respectively. Systolic and diastolic blood pressure were significantly lower in women compared to men for every quartile 1 and 2 of dietary calcium intake, higher in quartile 3, and not different in quartile 4 (Figure 1A and 1B). Dietary calcium intake in quartiles 3 and 4 were significantly associated with 38% and 55% greater odds of systolic hypertension (odds ratio (OR) Q3 1.375, P 0.006, 95% confidence interval (CI) 1.095, 1.728 and OR Q4 1.550, P < 0.0001, 95%CI 1.249, 1.923), but not with diastolic hypertension. After adjusting for age, gender, race, body mass index, serum creatinine, urine albumin:creatinine ratio, dietary sodium and potassium intakes, and the interaction term between gender and dietary calcium intake, only dietary calcium intake in quartile 3 was significantly associated with 82% lower odds of systolic hypertension (adjusted OR Q3 0.164, P 0.005, 95%CI 0.047, 0.578), while the association was greater and in the same direction for quartile 4, but it was not statistically significant (adjusted OR Q4 0.341, P 0.120, 95%CI 0.087, 1.326). Although there was an inverse association between dietary calcium intake and diastolic hypertension, it was not statistically significant. Gender was identified as an effect modifier, with a stronger positive association between the dietary calcium intake and systolic hypertension observed in female participants (Pinteraction 0.028). Conclusions: Dietary calcium intake and systolic hypertension, but not diastolic hypertension is inversely associated with a different magnitude between women and men. Additional longitudinal studies are required to further evaluate this relationship.