The Study of the Association of Serum Parathyroid Hormone Level with Obesity in Patients Admitted to a Tertiary Care Center in Basrah

Background: Parathyroid hormone (PTH) has been reported to have a positive correlation with insulin resistance and the development of the metabolic syndrome. This study aims to evaluate if there is an association between obesity and serum PTH levels. Methods: This case-control study was conducted at the Faiha Specialized Diabetes Endocrine and Metabolism Center in Basrah (Southern Iraq) from September 2018 to July 2019. A total of 230 patients were recruited for this study (103 male and 127 female), divided into 2 groups according to the BMI: <30 kg/m² were considered as the control group (83 persons) and ≥30 kg/m² were considered as obese persons (147 persons). The study groups were also subdivided into 3 groups according to the serum level of PTH: <40 pg/mL, 40–65 pg/mL, and >65 pg/mL. Results: The mean age of the obese and control groups was 44.39 ± 10.64 and 30.12 ± 8.95 years, respectively. About 46.25% of obese were men and 53.75% were women, while 42% of the control group were men and 58% were women. Serum PTH level was significantly higher ( p < 0.001) among obese persons with a mean level of 53.21 ± 19.58 pg/mL for obese and 37.63 ± 21.8 pg/mL for control. Vitamin D deficiency was seen in 84.4% of the obese group while in 71.1% of the control group ( p value 0.04). Females turned to have higher PTH levels than males in both the obese and the control group ( p value <0.001). However, age and the presence of diabetes mellitus were not associated with higher PTH levels ( p value 0.155 and 0.6, respectively). Conclusion: Obesity was associated with a higher serum PTH level related to the severity of vitamin D deficiency.