PTH predicts mortality in coronary angiography patients with T2DM

Serum parathyroid hormone (PTH) shows a significant and robust all-cause mortality in coronary angiography patients with type 2 diabetes mellitus (T2DM) compared with those without, a recent study has shown.

The investigators sought to examine the influence of T2DM on the power of PTH to predict mortality risk. They determined serum PTH levels in 904 consecutive Caucasian patients referred to coronary angiography for the evaluation of established or suspected stable coronary artery disease (CAD), including 235 patients with T2DM. Death was prospectively recorded over a mean follow-up period of 6.3 years.

No significant difference was seen in PTH at baseline between patients with and without T2DM (p=0.307). In Cox regression analysis, serum PTH level was found to be a strong predictor of all-cause mortality in patients with T2DM (hazard ratio [HR], 2.35, 95 percent confidence interval [CI], 1.37–4.03; p=0.002), but not in those without (HR, 1.04, 95 percent CI, 0.81–1.32; p=0.766).

A significant association was observed between PTH and T2DM (p=0.006), indicating a significant impact of PTH on mortality risk in patients with T2DM than in those without. Such association remained significant after adjustment for glycated haemoglobin A1c, diabetes duration, classical cardiovascular risk factors, serum levels of vitamin D, and kidney function (HR, 2.10, 95 percent CI, 1.10–4.10; p=0.030).

These findings suggest that elevated serum levels of PTH, one of the main regulators of calcium homeostasis and vitamin D metabolism, is a significantly strong predictor of all-cause mortality in diabetic patients, according to the investigators.