Dietary calcium intake and risk of type 2 diabetes: possible confounding by magnesium

Abstract

This study examined the association of dietary calcium intake with incident type 2 diabetes by a meta-analysis and explored the potential confounding by magnesium. Potential studies were identified by searching the PubMed database in September 2011. Prospective cohort studies that reported relative risks (RR) with 95% confidence intervals (CI) of type 2 diabetes for dietary calcium intake were selected. Results were combined using either a fixed-or random-effects model. Six prospective cohort studies comprising 264 268 participants and 11 225 reported cases were included. All combined random-effects metaanalysis yielded a significant pooled RR of 0.85 (95% CI 0.75 --0.97). However, a sensitivity analysis limited to four studies with control for magnesium yielded an attenuated, nonsignificant pooled RR of 0.94 (95% CI 0.85 --1.05). In conclusion, dietary calcium intake was not independently associated with risk of type 2 diabetes. The inverse association in prior observational studies may be partially confounded by magnesium intake.

Calcium intake: good for the bones but bad for the heart? An analysis of clinical studies

“…The results related to the intake of calcium-rich foods (e.g., milk, cheese, and yogurt) have demonstrated reduced mortality due to CVD (6,7,24) and reduced risks of MI (15,24) and stroke (21,23,24). These studies have also demonstrated neutral or beneficial profiles for factors such as atherosclerosis (26)(27)(28), blood pressure (29), plasma glucose (30,31) and body weight (32).…”

“…Studies have demonstrated beneficial or neutral effects of calcium dietary intake and medicinal supplementation on the development of diabetes (30,31,77,78). A meta-analysis involving 264,268 participants and 11,225 reported cases did not find a correlation between dietary calcium intake and diabetes (30).…”

“…A meta-analysis involving 264,268 participants and 11,225 reported cases did not find a correlation between dietary calcium intake and diabetes (30). Tong and cols.…”

“…Studies that have evaluated the intake of calcium food sources have reported neutral or protective effects on major cardiovascular outcomes, such as atherosclerosis (26)(27)(28), blood pressure (29), diabetes (30,31) and body weight (32) and the risks of infarction (15,24), stroke (21,23,24) and cardiovascular mortality (6,7,24). Moreover, such food sources result in the minimization of the risk of nephrolithiasis (33), which is known to be increased by medicinal calcium supplementation (34), and these food sources can provide other nutrients, such as proteins, which are useful in maintaining bone mass in adults (35,36) and can minimize the risks of malnutrition and sarcopenia, which are indirectly related to bone quality and the risk of fractures (37).…”

Magnesium and Type 2 Diabetes: An Update

“…Two meta-analyses of prospective studies concluded that Mg intake is inversely associated with type 2 diabetes [49,50]. Mg intake has been also strongly and inversely associated with the metabolic syndrome [37,51], while hypomagnesaemia has been independently associated with the development of impaired glucose tolerance [52].…”