High or low calcium intake increases cardiovascular disease risks in older patients with type 2 diabetes

BACKGROUND We investigated the effects of dietary calcium (Ca) and magnesium (Mg) intakes on cardiovascular disease risks in older patients with diabetes. METHODS In this cross-sectional study, 197 patients with type 2 diabetes aged 65 years and above were recruited. The 24-h dietary recalls and 1-week self-reported typical dietary intake patterns were collected. The Ca and Mg intakes of <67% of the recommended dietary allowance (RDA), 67%-100% of RDA, and >100% of RDA were defined as low, moderate, and high Ca and Mg intakes, respectively. Anthropometric measurements were determined and biochemical analysis of blood and urine was performed. RESULTS Our data indicated that 60.9% and 87.3% of our patients were Ca and Mg intakes below RDA, respectively. Patients whose Ca intake was high or low (81.2%) had significantly higher C-reactive protein (CRP) than those whose Ca intake was moderate (p = 0.043). Furthermore, patients whose Mg intake was low (87.3%) had significantly higher CRP than that of those who took adequate Mg (p = 0.025). The dietary Ca:Mg intake ratios were highly correlated with CRP, platelet counts, and red blood cell distribution (p < 0.05). A dietary Ca:Mg intake ratio of 2.0-2.5 was significantly correlated to lower CRP levels (p = 0.013). CONCLUSIONS High or low calcium intake increases cardiovascular disease risks. We suggest that "moderate" intake of 402-600 mg Ca/day (approximately 67%-100% of Taiwan RDA for Ca) and adequate Mg intake (or meeting RDA for Mg) with Ca:Mg intake ratio of 2.0-2.5 are important for reducing cardiovascular disease risks in older patients with diabetes.