Obesity and overweight are abnormal accumulation of body fat. Obesity as classified by World Health Organization (WHO) as body mass index (BMI) of ≥ 30 kg/m2 and ≥ 25 kg/m2 is considered as overweight. (1) BMI is calculated as weight in kilograms divided by the square of the height in meters. However, for Asian Indians population the BMI cut-off points are much lesser for obesity and overweight. BMI > 25 kg/m2 is considered as obesity and 23 to 24.99 kg/m2 is considered as overweight. (2)

Worldwide, at least 2.8 million people die each year as a result of being overweight or obese, and an estimated 35.8 million (2.3%) of global Disability-Adjusted life Years (DALYs) are caused by overweight or obesity. (3) In 2014, more than 1.9 billion adults were overweight. Of these over 600 million were obese. Overall, about 13% of the world’s adult population (11% of men and 15% of women) were obese and over (38% of men and 40% of women) were overweight. (4) It has been estimated that the number of obese individuals could increase to

1.12 billion in 2030, which would account for 20% of the world’s adult population. (5)

In India, in 2014, 9.8 and 20.0 million men and women were obese respectively. (7) In 2015- 16, the National Family Health Survey (NFHS-4) reported that prevalence of obesity is 18.04

% in men and 19.56 % in women. (8) NHFS-4 Key Indicators for Madhya Pradesh, prevalence of obesity is 21 %.(9) It is increasing in urban and rural population in India.(10) Among Indians, both abdominal and generalized obesity are present in male and female. (11) Generalized obesity is more in male and abdominal obesity in female. (12)

The presence of obesity is associated with adverse effects on health including metabolic complications in which numerous cytokines and hormones are involved. Obesity is associated with a higher risk of developing chronic diseases which includes diabetes, hypertension, osteoarthritis, and coronary artery disease (CAD) and moreover epidemiologic studies have found that obese adults have significantly higher mortality as compared with non-obese adults (13).

Adiponectin is an adipose-derived hormone with a variety of beneficial biological functions on glucose and lipid metabolism. (14,15) Adiponectin plays an effective role in cardioprotection and neuroprotection in ischemia /reperfusion injury and its anti- inflammatory and anti-atherogenic properties have been confirmed in various experimental models. (16) Adiponectin levels are inversely correlated with visceral obesity; therefore, high levels of adiponectin are negative correlated with obesity whereas low adiponectin levels exhibit a positive correlation. Serum levels of adiponectin are associated with metabolic syndrome and therefore metabolic syndrome development may be associated with obesity, adipose tissue content and hormonal levels (17).

Metformin, a biguanide class of oral hypoglycemic agents, is the first line drug for the treatment of type 2 diabetes mellitus. (20) Metformin is used clinically for the treatment of obesity and diabetes, and its mechanism of actions include the following: (1) lowers plasma glucose levels by inhibiting gluconeogenesis in liver, (2) decreasing the intestinal absorption of glucose, and (3) improving insulin sensitivity by increasing peripheral glucose uptake and utilization. (21) Additionally, metformin has a variety of pleiotropic effects including. improved lipid and cholesterol metabolism, decreased inflammation and inhibition of cell growth. ⁽²²⁾

This is a Prospective and randomized study was conducted in obese patients attending the outpatient department of Medicine in Index Medical College and Hospital over a period of 2 years over a period of 2 Years.

Inclusion Criteria:

• Male or female patients 18 years and above.
• Patients with obesity (BMI > 25 kg/m2).
• Patient willing to give informed written consent form.

Exclusion Criteria:

• Patients with history of Alcohol intake & Smoking.
• Patients with known history of Diabetes and hypertension.
• Patients with severe cardiac, liver and renal disease.
• Patients with GIT diseases.
• Patients with a history of lactic acidosis
• Patients with hypothyroidism and hyperthyroidism
• Patients taking vitamin B12, folate, steroid, oral contraceptives & hormone replacement therapy
• Pregnant and breast-feeding females.
• Patients with polycystic ovarian disease.
• All the obese patients attending outpatient department (OPD) of Medicine.
• Subjects willing to participate and written informed consent was obtained from each participant before study.
• Permission from treating consultant was obtained for subjects to participate in the study.
• Subjects were screened for selection criteria. Baseline evaluation included recording of demographic details, BMI, medical history, general and systemic examination and laboratory investigations, which included complete haemogram, hepatic and renal function tests and routine urine analysis. The eligible patients were enrolled as randomization.

Treatment:

Metformin was given at a daily dose of 1.0 gm BD for 3 months (Tab. Glycomet SR, USV Pharmaceutical Limited).

Follow-up Visits:

Follow-up visits were scheduled at the end of every month for 3 months for assessment, including measurement of weight and general and systemic examination.

Sample collection:

Samples of venous blood was collected from a forearm vein, at baseline and after 3 months of Metformin.

Blood samples were centrifuged at 3000 rpm for 15 min to separate the serum, and serum was stored at 4 °C for further assays.

Biochemical Parameters:

The following laboratory investigation was performed on sample of obese patients before and after Metformin therapy.

Biochemical assays: All biochemical assays were carried out with Automated Random access clinical chemistry analyzer ERBA Chem 7 with ERBA TEST REAGENT (Transasia Bio-medicals Ltd., India).

Procedure:

Blood samples were collected by vein puncture under all aseptic precautions from subjects using disposable syringes in fasting condition and Post Meal were collected in tubes containing sodium fluoride as an anticoagulant.

Adiponectin is estimated by DRG Diagnostic adiponectin Enzyme linked immune sorbent assay (ELISA) Kit.

Safety parameters:

• The safety was evaluated objectively by recording the ADR in the standard format of ADR reporting.
• The patients were explained the procedure of evaluation of safety parameters.
• Adverse Events Patients was advised to contact their Principal investigator if any adverse events occurred. The nature, time of onset, and severity of the event, the treatment needed, and any relation to the assigned study regimen was recorded. All serious adverse events were reported to the sponsor.

Statistical Analysis:

• The collected data was compiled in MS Excel sheet for analysis in Statistical Package for the Social Sciences (SPSS) version 25th was applied.
• The qualitative data was represented in the form of frequencies and percentage also represented in visual impression like bar diagram, pie diagram etc.
• For quantitative data was represented in the form of mean and standard deviation. To check significance difference between baseline and after three months effect of metformin on Adiponectin and ghrelin level in obese patient.
• A paired ‘t’ test was applied and also quantitative data was represented in the form of pie diagram and bar diagram.
• p value was check at 0.05 % level of significance

Table 1: Comparison of Mean Age:

In our study, maximum number of patients were in the age group of 51-60 years and least number of patients were ≤40 years of age. Mean age of patients were 53.43±5.34 years.

Table 2: Comparison of Mean Adiponectin (ng/ml) at baseline and after 3 months:

Mean ± SD in mg/dl, SD: Standard deviation, NS: Not significant,

* p<0.05 significant, ** p<0.001 highly significant

In Table 2, the mean of Adiponectin (ng/ml) is 12.01±2.35 at baseline (ng/ml) and after 3^rd month 23.88±2.09 (ng/ml). Serum Adiponectin levels within same group showed significant increased over a period of 3 months (p< 0.017).

Table 3: Comparison of Mean Fasting Blood Glucose level at baseline and after 3 months:

Mean ± SD in mg/dl, SD: Standard deviation, NS: Not significant, * p<0.05 significant,

** p<0.001 highly significant

In Table 3, the mean fasting blood glucose level at baseline was 96.54 mg/dl with SD of 8.53 mg/dl and after 3 months 71.62±7.35 mg/dl. These was statistically significant difference in mean Fasting Blood Glucose level at baseline versus after 3 months (p=0.025).

Table 4: Comparison of Mean Post Prandial Blood Glucose level at baseline and after 3 months:

Mean ± SD in mg/dl, SD: Standard deviation, NS: Not significant,

• p<0.05 significant, ** p<0.001 highly significant

In Table 4, the mean of PPBG level was 134.45±13.24mg/dl at baseline, followed by 103.63±15.43 mg/dl after 3^rd month, PPBG levels within same group showed significant reduction over a period of 3 months. These was statistically significant difference in mean Post Prandial Blood Glucose level at baseline versus 3^rd month of study period (P=0.017).

Table 5: Comparison of Mean HbA1c between at baseline and after 3 months:

Mean ± SD in mg/dl, SD: Standard deviation, NS: Not significant,

• p<0.05 significant, ** p<0.001 highly significant

In Table 5, the mean of HbA1c as 5.91±0.14% at baseline, 4.32±0.17 after 3^rd month. HbA1c levels within same group showed significant reduction over a period of 3 months (p< 0.0001).

In our study the mean of Adiponectin (ng/ml) is 12.01±2.35 at baseline (ng/ml) and after 3^rd month 23.88±2.09 (ng/ml). Serum Adiponectin levels within same group showed significant increased over a period of 3 months (p< 0.017). Similar to the findings of our study increased adiponectin levels have been observed in patients with obesity who are receiving metformin.

[24] Insulin and glucose levels induced by activation of the AMP-kinase pathways have been shown to directly affect adiponectin levels. Increased adiponectin levels observed in patients with obesity after metformin administration may be the result of reduced insulin resistance and insulin levels. [25]

Similar to our study, Sherafat-Kazemzadeh et al found that metformin treatment induced a significant reduction in BMI. [26] We performed a special study regarding the effect of metformin administration on BMI in patients with obesity for each adipocytokine. We found that metformin therapy could decrease BMI and blood concentrations of adiponectin. Thus, this may imply a significant correlation between adiponectin levels and BMI in patients with obesity. Such results are also reported by many other authors. Meanwhile, Apovian CM et al reported that only about 50% of subjects with obesity responded to metformin [27].

Similar to the findings of our study, increased adiponectin levels have previously been observed in patients with obesity who were receiving 850-mg metformin twice daily for 6 months. [28] Insulin and glucose levels induced by activation of the AMP-kinase pathways have been shown to directly affect adiponectin levels. Increased adiponectin levels observed in patients with Obesity after metformin administration may be the result of reduced insulin resistance and insulin levels.

McDonagh MS demonstrated a negative correlation between plasma adiponectin level and BMI in patients with obesity [29]. According to Kujawska-Luczak et al indicated no change in adiponectin concentration after treatment with 1000 mg of metformin daily for 6 months.

[30] These conflicting results could be explained by the relatively small sample size and difference in study populations, including differences in race, BMI, and severity of insulin resistance. Because of the complexity of the factors that influence the effect of metformin on adiponectin levels, we could not identify through our study the precise dose or duration of metformin therapy needed to maximize the increase in adiponectin concentration in patients with obesity. [31] Nevertheless, based on the limited data available, our study revealed that metformin treatment is associated with elevated serum adiponectin levels.

In our study the mean fasting blood glucose level at baseline was 96.54 mg/dl with SD of

8.53 mg/dl and after 3 months 71.62±7.35 mg/dl. These was statistically significant difference in mean Fasting Blood Glucose level at baseline versus after 3 months (p=0.025). The mean of PPBG level was 134.45±13.24mg/dl at baseline, followed by 103.63±15.43 mg/dl after 3^rd month, PPBG levels within same group showed significant reduction over a period of 3 months. These was statistically significant difference in mean Post Prandial Blood Glucose level at baseline versus 3^rd month of study period (P=0.017). While comparing with other studies metformin Suppress hepatic gluconeogenesis by activation of enzyme (AMP activated protein kinase) lowers plasma glucose levels by inhibiting gluconeogenesis in liver. [32]

In this study, the mean of HbA1c levels was 5.91±0.14% at baseline, 4.32±0.17 after 3^rd month. HbA1c levels within same group showed significant reduction over a period of 3 months (p< 0.0001). Improving insulin sensitivity by increasing peripheral glucose uptake and utilization by up-regulating expression of glucose transporter GLUT-4 in muscle and skeletal muscle and decreasing the intestinal absorption of glucose. Metformin increases plasma levels of glucagon-like peptide 1 (GLP-1) inhibiting glucagon release from α cell, and produces a feeling of satiety. [33]

Metformin remains equivocal as a primary treatment for obesity and as a weight loss agent. It may serve as an adjunct therapy for those patients who are at high risk for metabolic complications or are experiencing other sequelae of obesity. Its mechanistic effects on central hypothalamic signaling, incretin secretion and alteration of the gut microbiome establish attractive areas of research in identifying new targets for obesity treatment. The long-term impacts of metformin use on aging and sarcopenia have yet to be elucidated, but they may also provide important insights into optimizing body composition with age. In the meantime, metformin will continue to serve as a mainstay treatment in the management of T2D and confer multiple metabolic effects beyond glycemic control.

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