Zaccardi F, Webb D R, Carter P, Pitocco D, Khunti K, Davies M J, Kurl S, Laukkanen J A
Diabetes Research Centre, University of Leicester, Leicester, UK.
Diabetes Research Centre, University of Leicester, Leicester, UK.
Nutr Metab Cardiovasc Dis. 2015 Jun;25(6):562-8. doi: 10.1016/j.numecd.2015.02.013. Epub 2015 Mar 4.
Previous prospective studies showing a positive association between serum calcium and incidence of type 2 diabetes mellitus (T2DM) have relied on total calcium or an indirect estimate of active, ionized calcium (iCa). We aimed to assess this relationship using a direct measurement of iCa.
iCa and cardiometabolic risk factors were measured in a population-based sample of 2350 men without a known history of T2DM at baseline. Associations between iCa levels and incident cases of T2DM (self-reported, ascertained with a glucose tolerance test, or determined by record linkage to national registers) were estimated using Cox regression analyses adjusted for potential confounders. At baseline, mean (standard deviation) age was 53 (5) years and mean iCa 1.18 (0.05) mmol/L. During a median follow-up of 23.1 years, 140 new cases of T2DM were recorded. In a multivariable analysis adjusted for age, body mass index, systolic blood pressure, serum HDL-cholesterol, and family history of T2DM, there was no association comparing second (hazard ratio 0.84; 95% confidence interval 0.59-1.18), third (0.77; 0.52-1.14), or fourth (0.98; 0.69-1.39) vs first quartile of iCa (p for trend 0.538); further adjustment for C-reactive protein, physical activity level, and triglycerides did not change the estimates (p for trend 0.389).
In this study, we did not find evidence of an association between direct measurement of active calcium and risk of T2DM. Further studies are needed to confirm our findings and define the relationship between factors influencing indirect calcium estimation and incident T2DM.
既往前瞻性研究显示血清钙与2型糖尿病（T2DM）发病率之间存在正相关，这些研究依赖于总钙或活性离子钙（iCa）的间接估计值。我们旨在通过直接测量iCa来评估这种关系。
在基线时，对2350名无T2DM病史的男性人群样本测量了iCa和心血管代谢危险因素。使用针对潜在混杂因素进行调整的Cox回归分析估计iCa水平与T2DM发病病例（自我报告、通过葡萄糖耐量试验确定或通过与国家登记册的记录链接确定）之间的关联。基线时，平均（标准差）年龄为53（5）岁，平均iCa为1.18（0.05）mmol/L。在中位随访23.1年期间，记录了140例新的T2DM病例。在对年龄、体重指数、收缩压、血清高密度脂蛋白胆固醇和T2DM家族史进行调整的多变量分析中，将iCa的第二（风险比0.84；95%置信区间0.59 - 1.18）、第三（0.77；0.52 - 1.14）或第四（0.98；0.69 - 1.39）四分位数与第一四分位数进行比较时，未发现关联（趋势p值为0.538）；进一步对C反应蛋白、身体活动水平和甘油三酯进行调整并未改变估计值（趋势p值为0.389）。
在本研究中，我们未发现活性钙的直接测量值与T2DM风险之间存在关联的证据。需要进一步研究来证实我们的发现，并确定影响间接钙估计的因素与T2DM发病之间的关系。
