Calcium and phosphate concentrations and future development of type 2 diabetes: the Insulin Resistance Atherosclerosis Study

• Published in: Diabetologia 2014-07, Vol.57 (7), p.1366-1374
• Main Authors: Lorenzo, Carlos, Hanley, Anthony J., Rewers, Marian J., Haffner, Steven M.
• Format: Article
• Language: English
• Subjects: African Americans; Atherosclerosis; Atherosclerosis (general aspects, experimental research); Atherosclerosis - blood; Biological and medical sciences; Blood and lymphatic vessels; Calcium - blood; Cardiology. Vascular system; Diabetes; Diabetes Mellitus, Type 2 - blood; Diabetes Mellitus, Type 2 - diagnosis; Diabetes Mellitus, Type 2 - epidemiology; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Epidemiology; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Female; Follow-Up Studies; Glucose; Hispanic people; Human Physiology; Humans; Incidence; Insulin resistance; Insulin Resistance - physiology; Internal Medicine; Male; Medical sciences; Medicine; Medicine & Public Health; Metabolic Diseases; Middle Aged; Mortality; Phosphates - blood
• ISSN: 0012-186X; 1432-0428
• DOI: 10.1007/s00125-014-3241-9

Aims/hypothesis Low phosphate and high calcium concentrations have been linked to altered glucose tolerance and reduced insulin sensitivity in non-diabetic individuals. The aim of this study was to examine the relationships of calcium and phosphate levels and the calcium–phosphate product with the development of type 2 diabetes. Methods Participants were 863 African-Americans, Hispanics and non-Hispanic whites in the Insulin Resistance Atherosclerosis Study who were free of diabetes at baseline. The mean follow-up period was 5.2 years. The insulin sensitivity index (S I ) and acute insulin response (AIR) were directly measured using the frequently sampled IVGTT. Results Calcium concentration (OR per 1 SD unit increase, 1.26 [95% CI 1.04, 1.53]) and calcium–phosphate product (OR 1.29 [95% CI 1.04, 1.59]) were associated with incident diabetes after adjustment for demographic variables, family history of diabetes, and 2 h glucose. The relationship between phosphate concentration and progression to diabetes was close to statistical significance (OR 1.21 [95% CI 0.98, 1.49]). Calcium concentration (OR 1.37 [95% CI 1.09, 1.72]) and calcium–phosphate product (OR 1.39 [95% CI 1.09, 1.77]) remained associated with incident diabetes after additional adjustment for BMI, plasma glucose, S I , AIR, C-reactive protein, estimated GFR, diuretic drugs and total calcium intake. Conclusions/interpretation Elevated serum calcium and calcium–phosphate product are associated with increased risk of developing type 2 diabetes independently of measured glucose, insulin secretion and insulin resistance. Future studies need to analyse the role of calcium–phosphate homeostasis in the pathophysiology of diabetes.