A pooled analysis of large-scale registry studies by UK researchers suggests that bariatric surgery is associated with reduced long-term all-cause mortality and incidence of obesity-related diseases (new-onset diabetes, high blood pressure, high cholesterol and heart disease etc) in patients with obesity for the whole operated population. The outcomes highlight that broader (increased) access to bariatric surgery for people with obesity may reduce the long-term sequelae of this disease and provide population-level benefits.
For the study, ‘Association of bariatric surgery with all-cause mortality and incidence of obesity-related disease at a population level: A systematic review and meta-analysis’, published in Plos Medicine, the researchers performed a systematic literature search and found 18 studies suitable for inclusion encompassing some 1,539,904 patients with 269,818 receiving bariatric surgery and 1,270,086 control patients.
The types of surgery were gastric bypass (n=137,578, 51%), sleeve gastrectomy (n=58,916, 22%), adjustable gastric band (n= 52,973, 20%), vertical banded gastroplasty (n=6,397, 2%), biliopancreatic diversion (with or without duodenal switch) (n=1,002, 0.4%) and an alternative procedure or unspecified operation (n=12,952, 5%). Median patient follow-up across all studies was 59 months (range 18 to 144 months).
"Healthcare providers may use the data on relative risk reduction as part of the discussion with patients considering bariatric surgery.”
The authors report that 11 studies found a significant reduction in relative risk of long-term all-cause mortality for patients following bariatric surgery compared to controls with a pooled odds ratios (PORs) of 0.62 (95% CI 0.55 to 0.69, p<0.001). A further three studies reported significantly reduced relative risk of cardiovascular mortality for patients following bariatric surgery vs controls (POR 0.50, 95% CI 0.35 to 0.71, p<0.001).
In addition, the study found:
- Six studies reporting a reduction in incident T2DM after bariatric surgery vs controls (POR 0.39, 95% CI 0.18 to 0.83, p=0.010)
- Five studies found that incident hypertension was reduced after bariatric surgery vs controls (POR 0.36, 95% CI 0.32 to 0.40, p<0.001)
- One study reported incident obstructive sleep apnoea relative to controls (therefore it was not possible to do a pooled analysis) with a reduced rate of new-onset obstructive sleep apnoea in patients undergoing bariatric surgery (new-onset obstructive sleep apnoea rate of 1.1%), vs controls (2.0%) (HR 0.55, 95% CI 0.37–0.82, p=0.004)
- Two studies reported significantly reduced incident dyslipidaemia following bariatric surgery vs controls (POR 0.33, 95% CI 0.14 to 0.80, p=0.010)
- Five studies reported significantly reduced incident ischemic heart disease after bariatric surgery vs controls (POR 0.46, 95% CI 0.29 to 0.73, p=0.001)
- Two studies reported the rate of incident cardiac failure and found no statistically significant protective association with bariatric surgery (POR 0.23, 95% CI 0.05 to 1.10, p=0.066)
- One study reported incident venous thromboembolism in bariatric surgery patients relative to controls (therefore it was not possible to undertake a pooled analysis), demonstrating a reduced incidence of new-onset venous thromboembolism in bariatric surgery patients (1.7%), vs controls (4.4%) (HR 0.60, 95% CI 0.43 to 0.84, p=0.003)
Adjusted ORs for incident comorbidities revealed the same patterns with reduced incidence of T2DM (POR 0.28, 95% CI 0.11 to 0.73, p=0.009), hypertension (POR 0.32, 95% CI 0.21 to 0.47, p<0.001), ischemic heart disease (POR 0.67, 95% CI 0.49 to 0.90, p=0.009), and cardiac failure (POR 0.43, 95% CI 0.29 to 0.64, p<0.001) in bariatric surgical patients vs controls.
“To our knowledge, this is the first published study of pooled data from population-based studies of incident disease following bariatric surgery. Our results represent real-world data that may be generalisable to routine clinical practice…This meta-analysis of large-scale registry studies indicates that patients receiving bariatric surgery have improved long-term mortality rates compared to controls at a population level,” the authors concluded. “They also have significantly reduced incidence of obesity-related disease including T2DM, hypertension, dyslipidaemia and ischemic heart disease. Healthcare providers may use the data on relative risk reduction as part of the discussion with patients considering bariatric surgery.”
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