Avaliação da ingestão habitual de cálcio e sua associação com a concentração intracelular de cálcio, adiposidade corporal, perfil metabólico, biomarcadores inflamatórios, pressão arterial e função endotelial

Abstract

The inverse association between dietary calcium intake and body adiposity and blood pressure is established in epidemiological studies. Experimental data suggest that it may be mediated by alterations in intracellular calcium concentration ([Ca]i). There are few studies evaluating the relationship beween dietary calcium and [Ca]i. The objective of the present study was to evaluat the association of dietary calcium with [Ca]I, body adiposity, metabolic profile, inflammatory biomarkers, blood pressure, and endothelial function in women. It was conducted an observational and cross-sectional clinical trial, including 76 women with pre-menopausal status who were submitted to the following evaluations: dietary intake (by a food frequency questionnaire); [Ca]I in erythrocytes (by atomic absorption spectrometry); body adiposity (by body mass index [BMI] and electrical bioimpedance; abdominal adiposity (by waist circumference and waist-to-hip-ratio; metabolic profile (by assessing plasma glucose, total cholesterol and fractions, insulin and HOMA-IR); inflammatory biomarkers (adiponectin and C-reactive protein); endothelial function (by analyzing adhesion molecules and by peripheral artery tonometry [PAT]); and blood pressure. Calcitriol, parathyroid hormone, and serum and urinary calcium completed calcium metabolism. Participants were stratified into two groups according to their mean usual dietary calcium intake: low calcium group (LCG; n=32; dietary calcium intake <600mg/d) and high calcium group (HCG; n=44; dietary calcium intake &#8805;600mg/d). Após ajustes para fatores de confundimento (idade, ingestão de energia, bebida alcoólica, proteína, carboidratos e lipídios), o Grupo AIC, em comparação com o BIC, apresentou valores significativamente mais baixos de IMC (25,6±5,3 vs 26,9 ± 6,0 kg/m²; p=0,02), PC (84,4±13,6 vs 87,8±15,3cm; p=0,04), % GC (31,1±5,9 vs 33,3±5,6 %; p=0,003), pressão arterial diastólica (68,2±10,8 vs 72,4±11,2 mm Hg; p=0,04) e pressão arterial média (80,13±10,94 vs 83,86±11,70 mmHg; p=0,04); e significativamente mais altos de HDL-colesterol (58,6±12,2 vs 52,9±12,2 mg/dL; p=0,004) e adiponectina (34572,1 ± 19472,8 vs 31910,3±19385,1 ng/mL; p=0,05). A [Ca]i e as outras variáveis avaliadas não diferiram entre os grupos, mesmo após ajustes. Neste estudo realizado com mulheres, o maior consumo de cálcio se associou com valores mais baixos de adiposidade corporal total e central, pressão arterial diastólica e média; além de valores mais elevados de HDL-colesterol e adiponectina. After controlling for potential confounders (age, dietary energy, protein, carbohydrates and lipids and alcohol intake), HCG, in comparison to LCG, showed significantly lower vlaues of BMI (25.6±5.3 vs 26.9 ± 6.0 kg/m²; p=0.02), waist circumference (84.4±13.6 vs 87.8±15.3cm; p=0.04), % body fat (31.1±5.9 vs 33.3±5.6 %; p=0.003), diastolic blood pressure (68.2±10.8 vs 72.4±11.2 mm Hg; p=0.04) e mean blood pressure (80.13±10.94 vs 83.86±11.70 mmHg; p=0.04); and significantly higher values of HDL-cholesterol (58.6±12.2 vs 52.9±12.2 mg/dl; p=0.004) and adiponectin (34.57±19.47 vs 31.91±19.39 μg/ml; p=0.05). There was no difference between groups in relation to [Ca]i and other parameters evaluated, even after adjusting for confounding factors. In this study, higher dietary calcium intake was associated with lower values of total and abdominal adiposity, diastolic and mean blood pressure; and with higher values of HDL-cholesterol e adiponectin