Weight Loss Following Bariatric Surgery in People with or without Metabolic Syndrome: A 5-Year Observational Comparative Study

Abstract

Aim: Whilst bariatric surgery is the most effective treatment for severe obesity, the aim of this study was to evaluate whether postoperative weight loss is similar in patients with or without metabolic syndrome.

Methods: We performed a 5-year observational retrospective comparative cohort analysis of bariatric surgery in 333 patients (72% women) without (Group A, n = 133) or with (Group B, n = 200) metabolic syndrome at baseline.

Results: Overall mean (SD) baseline body mass index was 51.7 (7.5) with no significant difference between groups. Overall mean percent total weight loss (%TWL) was 31.9% by 24 months after surgery. Although %TWL was greater in Group A (34.9%) than in Group B (30.2%, p = 0.006) at 24 months, there were no significant differences between groups subsequently up to 60 months of follow-up. Systolic and diastolic blood pressures and lipid profiles improved in both groups. In patients with metabolic syndrome at baseline, mean HbA1c reduced by 36.4% at 12 months and was sustained over the study period.

Conclusions: We report that bariatric surgery results in comparable long-term weight loss in patients with or without metabolic syndrome alongside expected improvements in metabolic comorbidities.

Keywords: gastrectomy; gastric bypass; insulin resistance; metabolic syndrome; weight loss.

Figure 1

Weight loss outcomes after bariatric surgery over 60 months of follow-up. (A) Body mass index (BMI) in all patients (ALL, grey trace) and categorised by absence of metabolic syndrome (Group A, blue trace) or presence of metabolic syndrome (Group B, orange trace). (B) Percent total weight loss (%TWL) in all patients (ALL, grey trace) and categorised by absence of metabolic syndrome (Group A, blue trace) or presence of metabolic syndrome (Group B, orange trace). (C) %TWL in women (Women, red trace), who constituted 72% of the total cohort, categorised by absence of metabolic syndrome (Group A, blue trace) or presence of metabolic syndrome (Group B, orange trace). (D) %TWL in patients who underwent Roux-en-Y gastric bypass (Bypass, green trace), who constituted 84% of the total cohort, categorised by absence of metabolic syndrome (Group A, blue trace) or presence of metabolic syndrome (Group B, orange trace). Numbers of patients contributing data at each timepoint are depicted above the x-axis. Error bars, standard errors of the means. * Significant difference at timepoint between Group A and Group B (independent samples Student t test).

Figure 2

Glycaemic outcomes after bariatric surgery. (A) Glycated haemoglobin (HbA1c) in all patients (ALL, grey trace) and categorised by absence of metabolic syndrome (Group A, blue trace) or presence of metabolic syndrome (Group B, orange trace). (B) HbA1c in patients with type 2 diabetes (T2D, purple trace) and in females (Women, red trace), who constituted 62% of the people with T2D. Numbers of patients contributing data at each timepoint are depicted above the x-axis. Error bars, standard errors of the means. * Significant difference at timepoint compared with baseline (paired samples Student t test).

Figure 3

Lipid and blood pressure outcomes after bariatric surgery in all patients (ALL, grey trace) and categorised by absence of metabolic syndrome (Group A, blue trace) or presence of metabolic syndrome (Group B, orange trace). (A) Non-high-density lipoprotein cholesterol (Non-HDLc). (B) High-density lipoprotein cholesterol (HDLc). (C) Systolic blood pressure (sBP). (D) Diastolic blood pressure (dBP). Numbers of patients contributing data at each timepoint are depicted above the x-axis. Error bars, standard errors of the means. * Significant difference at timepoint compared to baseline (paired samples Student t test).