Targeting Parathyroid Hormone Level in Diabetic Patients With Stage 3 to 5 Chronic Kidney Disease: Does Metabolic Syndrome Matter?

Objectives

Patients with type 2 diabetes have lower intact parathyroid hormone (iPTH) levels when compared with non-diabetics. Patients with metabolic syndrome (MetSyn) have increased iPTH levels than normal subjects. We hypothesized that patients with type 2 diabetes and MetSyn might have higher iPTH levels as compared with those without MetSyn.

Methods

The study had an observational design. A total of 84 patients with type 2 diabetes and stage 3 to stage 5 chronic kidney disease (CKD) were recruited (male/female, 40/44).

Results

A total of 59 (70.2%) patients had MetSyn. Progress from stage 3 to stage 5 CKD lead to a significant increase in iPTH levels (P-trend = .018). Patients with diabetes and MetSyn had lower high-density lipoprotein cholesterol (P = .018) and higher waist circumference (P = .019), systolic blood pressure (P = .036), fasting plasma glucose (P = .005), HbA1c levels (P = .012), triglyceride (P < .0001), and iPTH (P = .009) as compared with patients without MetSyn. Serum iPTH was negatively correlated with estimated glomerular filtration rate, as measured by Modification of Diet in Renal Disease formula (r = −0.339, P = .002), serum calcium (r = −0.232, P = .037), glucose (r = −0.240, P = .03), and HbA1c (r = −0.301, P = .04) and was positively correlated with urinary albumin excretion rate (r = +0.225, P = .044). After adjusting for potential confounders, logPTH was higher in patients with MetSyn as compared with those without among type 2 diabetic patients with CKD (P = .039).

Conclusions

MetSyn might influence iPTH levels in type 2 diabetic patients with stage 3 to 5 CKD. However, it is still debatable whether MetSyn should be taken into account in determining target iPTH levels in type 2 diabetic patients with CKD.