DIAGNOSTIC VALUE OF THYROTROPIC HORMONE IN PATIENTS WITH DIABETES MELLITUS

Abstract

SUMMARY. Type 2 diabetes mellitus (T2DM) remains one of the most pressing medical and social issues of our time. According to international organizations, nearly one billion people worldwide are affected by diabetes, with approximately 90 % of them diagnosed with T2DM. The incidence of T2DM continues to rise globally due to population aging, urbanization, sedentary lifestyles, unhealthy diets, and the obesity epidemic. Alarmingly, T2DM is increasingly being diagnosed in young adults and adolescents.

One of the most common comorbid endocrine disorders in T2DM is thyroid dysfunction, which ranks second in frequency after diabetes itself. It can manifest as clinically evident hypothyroidism or hyperthyroidism, as well as asymptomatic (subclinical) forms. The prevalence of thyroid dysfunction depends on various factors, including age, sex, iodine intake, race, and geographical location.

Recent studies show a growing frequency of hypothyroidism (both overt and subclinical) among patients with T2DM, with elevated levels of thyroid-stimulating hormone (TSH) often observed even when free triiodothyronine (T3) levels are normal or decreased. Thyroid dysfunction is significantly more common among individuals with diabetes compared to the general population, indicating a strong pathophysiological link between these endocrine disorders.

The relevance of this study lies in the need for early detection of thyroid dysfunction in patients with T2DM, which would enable timely correction of metabolic disturbances, prevention of complications, and improvement in patients’ quality of life.

The aim – to  conduct a comparative analysis of thyroid-stimulating hormone (TSH) levels in patients with and without type 2 diabetes mellitus.

Material and Methods. A total of 60 ambulatory patients were examined. Among them, 20 were practically healthy individuals (control group), 20 had hypothyroidism without diabetes (group 1), and 20 had hypothyroidism combined with T2DM (group 2). The average age of patients was 58±3 years.

TSH levels (reference range: 0.27–4.20 mIU/L) were measured using the Cobas 6000 immunoassay analyzer with Roche Diagnostics (Switzerland) test systems. Glucose levels were determined using standard kits on the COBAS INTEGRA® 400 biochemical analyzer (Roche Diagnostics).

Results. According to the results, TSH levels in group 1 were 1.5 times higher than in the control group (p<0.05). In group 2, TSH levels were 1.8 times higher than the control (p<0.05) and 1.2 times higher than in group 1 (p<0.05).

Similarly, glucose levels in group 1 were 1.2 times higher than in the control group (p<0.05), while group 2 had glucose values 1.7 times higher than the control group (p<0.05) and 1.4 times higher than group 1 (p<0.05).

Conclusions. Patients with type 2 diabetes mellitus frequently exhibit elevated TSH levels, even with normal thyroid hormone concentrations, indicating the presence of subclinical hypothyroidism. This hormonal imbalance may affect carbohydrate metabolism, hinder glycemic control in T2DM, and contribute to insulin resistance. The established association between T2DM and thyroid dysfunction emphasizes the need for routine monitoring of TSH levels in diabetic patients for early diagnosis of thyroid disorders, individualized treatment, and prevention of metabolic complications.