Assessment of Metabolic Syndrome Components in Patients with Normocalcemic Hyperparathyroidism: A Retrospective Study

Objective: Normocalcemic hyperparathyroidism is characterized by elevated parathormone levels persisting for 3 months or longer despite normal serum Ca levels. This study aimed to retrospectively compare the prevalence of individual metabolic syndrome components between patients with normocalcemic hyperparathyroidism and an age- and sex-matched control group.

Methods: Data of 82 normocalcemic hyperparathyroidism patients and 80 control subjects with normal parathormone and calcium levels were reviewed retrospectively. Those meeting 3 or more of the 2001 metabolic syndrome diagnostic criteria of the US National Cholesterol Education Program Adult Treatment Panel III were considered as having metabolic syndrome. Also, Turkish waist circumference cutoff values were used to identify abdominal obesity and to estimate the metabolic syndrome frequency.

Results: Considering that higher body mass index of normocalcemic patients would confound the analysis, analysis of covariance adjusted for body mass index was used to compare the groups, which showed increased waist circumference, waist/hip ratio, parathormone, 25 OH vitamin D3, fasting plasma glucose, and total cholesterol and low-density lipoprotein-cholesterol levels in normocalcemic hyperparathyroidism patients than controls. The prevalence of metabolic syndrome among normocalcemic hyperparathyroidism patients was 32.9% (22.5% in controls) using the National Cholesterol Education Program Adult Treatment Panel III criteria versus 34.1% (23.8% in controls) using the Turkish waist circumference cutoff values.

Conclusion: The percentage of patients meeting the metabolic syndrome criteria was higher compared to the control group. Even in the case of normocalcemic hyperparathyroidism, which is considered to be a milder condition, the prevalence of metabolic syndrome was relatively higher than in the control group, suggesting that normocalcemic hyperparathyroidism may be a cardiovascular risk factor by predisposing to metabolic syndrome.

Cite this article as: Baykut OA, Elbüken G, Tokuç B, Shafi Zuhur S. Assessment of metabolic syndrome components in patients with normocalcemic hyperparathyroidism: A retrospective study. Endocrinol Res Pract. 2023;27(1):8-14.