Effects of successful parathyroidectomy on metabolic cardiovascular risk factors in patients with severe primary hyperparathyroidism.

OBJECTIVE

To evaluate the effect of parathyroidectomy on metabolic abnormalities associated with cardiovascular disease in patients with primary hyperparathyroidism (PHPT).

METHODS

Thirty-four patients with PHPT (aged 51.0 ± 11.8 years, mean ± standard deviation) underwent assessment before and 1 year after successful parathyroidectomy. A control group of 42 normocalcemic healthy subjects, matched for age and body mass index, was also examined at baseline. We measured serum lipids, glucose, insulin, uric acid, calcium, parathyroid hormone, C-reactive protein, and bone density. Insulin resistance index was evaluated by homeostasis model assessment, and the presence of metabolic syndrome was determined. Because of multiple tests, the level of statistical significance was set at .01.

RESULTS

After parathyroidectomy, there was a decrease in diastolic blood pressure (P<.02) and in serum concentrations of uric acid (P<.04) and insulin (P<.009). No difference was observed in rates of metabolic syndrome in patients before and 1 year after parathyroidectomy (23.5% versus 17.6%; P>.46). Insulin resistance index values were also unchanged from before to after parathyroidectomy (1.3 ± 0.9 and 1.1 ± 0.9, respectively; P>.68). A substantial increase in spine bone density (5%; P<.05) was noted postoperatively. Multivariate logistic regression analysis, after adjustment for age and body mass index, revealed that parathyroidectomy did not lead to a significant decrease in likelihood of cardiovascular risk-odds ratio (OR), 1.82; 95% confidence interval (CI), 0.53 to 6.21 (P>.34) for the metabolic syndrome and OR, 0.82; 95% CI, 0.17 to 3.88 (P>.8) for the insulin resistance index.

CONCLUSION

In this study, surgical treatment had no beneficial effect on cardiovascular risk, as assessed by the metabolic syndrome and insulin resistance markers in patients with PHPT 1 year after parathyroidectomy.