Influence of sleeve gastrectomy on bone marrow fat in metabolic syndrome patients with and without diabetes: a prospective follow-up study.

Objectives: To evaluate bone marrow fat concentration changes after sleeve gastrectomy in metabolic syndrome patients with and without diabetes.

Methods: A total of 58 metabolic syndrome patients (29 metabolic syndrome patients with diabetes (35.10 years ± 6.62) and 29 metabolic syndrome patients without diabetes (35.07 years ± 6.47)) who underwent sleeve gastrectomy received prospective follow-up for 2 years. Echo asymmetry, least square estimation-MRI, and laboratory tests were performed on all patients before and 2 years after surgery. The differences between baseline and end-of-study parameters were analyzed with the paired Student's t test. In addition, the associations of vertebral bone marrow fat concentration (denoted by proton density fat fraction, PDFF) with other variables were determined using multiple linear regression analysis.

Results: Bone proton density fat fraction decreased significantly among patients with diabetes (from 38.62 ± 8.01 to 34.54 ± 7.54, P = 0.003) and without diabetes (from 36.82 ± 8.80 to 35.09 ± 8.33, P = 0.011) after sleeve gastrectomy. Among patients with diabetes, multivariable predictors of changes in proton density fat fraction by descending order of standardized coefficient were changes in HbA1c (2.690, P < 0.001), baseline HbA1c (2.354, P < 0.001), changes in insulin (0.627, P < 0.001), changes in low-density lipoprotein cholesterol (0.597, P = 0.013), and changes in C-peptide (-0.664, P = 0.001). Among patients without diabetes, multivariable predictors of changes in proton density fat fraction were changes in low-density lipoprotein cholesterol (1.486, P < 0.001), changes in high-density lipoprotein cholesterol (0.460, P = 0.003), baseline low-density lipoprotein cholesterol (0.438, P = 0.014), changes in triglyceride (0.383, P = 0.007), and changes in total cholesterol (-1.614, P < 0.001).

Conclusions: Sleeve gastrectomy may decrease bone marrow fat concentration of MetS patients regardless of diabetes status. Changes in bone marrow fat concentration may be influenced by different factors based on diabetes status.