Impact of MBS on Body Composition, Basal Metabolic Rates and Muscle Functions in Morbid Obese Patients

In this study, morbidly obese patients undergoing bariatric surgery will be assessed at baseline and followed by 3rd and 6 months to evaluate various physiological and biochemical changes

• Anthropometric Measurements:

Height (Ht) - measured using a stadiometer Weight (Wt) - measured using a digital weighing scale Body Mass Index (BMI) - calculated as Weight/(Height)2. Kg/m² Waist-Hip Ratio (WHR) - using a measuring tape to assess fat distribution

• Body Composition Analysis. Body composition analysis will be done using multi-frequency BIA (model InBody370S). Cases will be asked to ensure sufficient hydration before undergoing BIA and patients with electrical implants will be refrained from using BIA. The machine will provide following parameter PBF (Percentage Body Fat) - to assess total fat content SMM (Segmental Muscle Mass) - to evaluate muscle mass in individual limbs and trunk SFM (Segmental Fat Mass) - to quantify regional fat distribution SMI (Skeletal Muscle Index) - to assess skeletal muscle mass adjusted for height
• Basal Metabolic Rate (BMR):

Measured using BIA, Resting energy expenditure will be measured using an indirect colorimeter if feasible.

• Muscle Function Assessment:

Muscle Strength: Upper limbs muscle strength will be assessed by using Hand held dynamometer, which will measure hand grip strength(HGS).Three readings will be taken at an interval of 1 minute of rest. The average of 3 readings will be taken as HGS for each arm.A value of less than 28 in men and less than 18 in women will be considered as low HGS(6).

Muscle Performance:

A 6 meter walk test is a reliable test to assess muscle function or physical performance. A gait speed of less than 1 metre/second will be considered as reduced physical performance

• Inflammatory Markers:

Interleukin 6 (IL 6) High sensitivity C reactive protein (Hs CRP) Erythrocyte Sedimentation Rate (ESR)

• Metabolic Parameters:

In this study, a comprehensive panel of metabolic and biochemical parameters will be assessed to evaluate the systemic effects of bariatric surgery. Glycemic control will be monitored through FBS, PPBS and HbA1c. Thyroid function will be evaluated by measuring thyroid stimulating hormone (TSH). Renal function will be assessed using serum urea and creatinine levels, urine ACR, while liver function will be evaluated through total bilirubin, AST, ALT, ALP estimation. Lipid metabolism will be examined by measuring total cholesterol, triglycerides, LDLand HDL. Additionally, serum calcium, VitD3 will be included to monitor bone and mineral metabolism, which may be affected by significant weight loss or changes in nutritional status postoperatively. These parameters will provide a holistic view of the physiological changes and health improvements resulting from bariatric surgery.

Follow-up: 3 and 6 months postoperative

Statistical analysis plan:

Data will be managed in Microsoft Excel and analysed using SPSS version 26. Numerical data like BMR, fat mass, etc., will be shown as mean ± SD or median with range.Categorical values like gender and type of surgery will be expressed as percentages.Kolmogorov-Smirnov test will be used to check for normality of continuous variables.Depending on data type, either parametric or non-parametric tests will be applied. All final outcomes will be shown with 95% confidence intervals.A p-value of <0.05 will be kept as a significant threshold.

Inclusion criteria

• BMI > 35 with or without obesity-related comorbidities Planned for Bariatric and Metabolic Surgery

Exclusion criteria

• Known endocrine disorders (Cushing's and Untreated hypothyroidism)
• History of prior bariatric surgery
• Inability to comply with follow-up scheduleLost to follow-up before 3 months post-treatment