Pathology of carbohydrate metabolism in primary hyperparathyroidism: epidemiological and clinical characteristics

Abstract

Primary hyperparathyroidism (PHPT) is characterized by disorders of not only mineral metabolism, but also other kinds of the human metabolism. Due to the increased frequency of cardiovascular risk factors among patients with PHPT, the study of the carbohydrate metabolism pathology in this cohort of patients will allow developing optimal approaches to their timely diagnosis and treatment.Aim. To determine the frequency and describe the clinical features of carbohydrate metabolism disorders in patients with PHPT.Material and methods. A single-center retrospective study of adults with PHPT was carried out with an assessment of the main parameters of mineral and carbohydrate metabolism before surgical treatment of the disease. The exclusion criteria were the absence of PHPT remission or a recurrence of the disease after parathyroidectomy; pregnancy, lactation. The frequency of various disorders of carbohydrate metabolism in PHPT, the comparative characteristics of mineral parameters in patients with and without them, as well as the severity of type 2 diabetes mellitus in PHPT were determined. In addition, potential relationships between the parameters of various types of metabolism have been studied.Results. The study was based on a clinical information of 367 patients with PHPT, most of whom had a symptomatic form of the disease. The overall incidence of prediabetic disorders was 4,9% (95% CI: 3-8). Type 2 diabetes mellitus was previously diagnosed in 45 patients (12%, 95% CI: 9-16), there were no cases of first diagnosed diabetes mellitus. Individuals with impaired carbohydrate metabolism had a statistically significantly higher body mass index and lower values of osteocalcin (27,2 [24,2; 30,4] kg/m2 vs 32,7 [28,1; 39,4 kg/m2 and 48,1 [34; 76,3] ng/mL vs 33,1 [20,8; 51,8] ng/mL, respectively, for all parameters p<0,001). Among patients with type 2 diabetes mellitus, 36 people (80%) took hypoglycemic therapy, 14 of which received metformin monotherapy and 8 received two-component therapy, including metformin. 5 people were on insulin therapy. Diabetic nephropathy was diagnosed in 36,4% of patients, 15,4% had signs of diabetic retinopathy, symptoms of diabetic distal neuropathy were observed in 61,9% of patients with PHPT. Fasting glucose and glycated hemoglobin were negatively correlated with bone metabolism, and also expectedly depended on the glomerular filtration rate.Conclusion. Among patients with PHPT, type 2 diabetes mellitus is more common than in the general population. The likely reason of this may be insulin resistance, that can be caused by the effects of bone metabolites, primarily osteocalcin. In most cases, metformin makes it possible to achieve compensation for diabetes mellitus in PHPT.