The Effects of Obesity on Bone Turnover Markers in Diabetic Patients with Diabetic Ketosis or Ketoacidosis

Purpose: Despite the fact that diabetes individuals are often associated with a higher risk of bone fracture, our previous research demonstrated that Diabetic ketosis (DK) or ketoacidosis (DKA) induced significant alterations in bone biomarkers. It is unknown whether there is a difference in bone metabolism between obese and non-obese diabetic populations while they are in DK or DKA; hence the current study will investigate this further to aid in the prognosis and prediction of bone fracture risk in patients with different BMIs. Methods: We categorized patients into four groups based on their BMI utilizing data from our hospital's medical record system from 2018 to 2020 in the Department of Endocrinology: obese DK or DKA patients (OB+DK/DKA, n = 41), non-obese DK or DKA patients (DK/DKA, n = 201), obese type 2 diabetes patients without DK or DKA (OB+T2D, n = 93), and patients with type 2 diabetes only (T2D only, n = 304). The comparisons were made on glycosylated hemoglobin (HbA1c), body mass index (BMI), fasting plasma C-peptide (FPCP), and plasma lipids, in addition to bone metabolism indicators such as total 25-OH-VitD3 (25-OH-VitD3), N-terminal middle molecular fragment of osteocalcin (NMID), -C terminal cross-linking telopeptide of type 1 collagen (-CTX), parathyroid hormone (PTH), and blood calcium (Ca²⁺). Results: The OB+DK/DKA group had a lower average age (p < 0.05) than the DK/DKA group, while the DK/DKA group had a significantly lower FPCP (p < 0.05). The 25-OH-VitD3 levels of DK/DKA patients were considerably lower than those of the T2D-only group (p < 0.05). In contrast, NMID and Ca²⁺ levels were significantly lower than those of non-ketosis or acidosis patients (p < 0.05), and PTH levels in the DK/DKA group were significantly lower than those of OB+ T2D patients (p < 0.05). In contrast, the β-CTX of the DK or DKA group (OB+DK/DKA and DK+DKA) was significantly greater than that of the non-DK or DKA group (p < 0.05), although there was no significant difference in blood phosphorus between OB+DK/DKA and DK/ DKA (p > 0.05). The levels of thyroid-stimulating hormone (TSH) and free T4 (FT4) did not differ significantly among the four groups (p > 0.05); however, the levels of total T3 (TT3), T4 (TT4), and free T3 (FT3) were significantly lower in the DK/DKA group (p < 0.05); the ratio of TT3 to TT4 (TT3/TT4) was significantly decreased in the DK/DKA group, whereas the ratio of FT3/FT4 was significantly lower (p < 0.05). Conclusion: Obese patients with DK or DKA have a younger onset age, superior pancreatic function, and better blood glucose management than non-obese patients with DK/DKA. Despite having higher bone absorption signals than non-DK/DKA patients, OB+DK/DKA patients have stronger bone formation markers than non-obese DK/DKA patients, according to a recent study. Changes in markers of bone metabolism may be linked to non-thyroidal illness syndrome in cases of DK or DKA.