Updated: Jan 12
Dr. Jaideep Raj Rao says the procedure increases life expectancy in patients with diabetes and obesity.
The rising prevalence of obesity and overweight exerts a major public health toll worldwide, having contributed to five million deaths and 160 million disability-adjusted life-years in 2019.
High body-mass index — or more precisely, visceral adiposity (fat) — is a cardiovascular risk factor that is a component of metabolic syndrome, a collection of conditions that can increase your chances of diabetes, coronary heart disease, hypertension, certain cancers, and premature death. Consequently, clinical practice guidelines in endocrinology and cardiology emphasize weight control and weight-loss interventions through behavioural and lifestyle modification, pharmacotherapy, and bariatric surgery, as a cornerstone of lowering macrovascular disease risk.
Bariatric surgery involves carrying out standard weight-loss procedures to treat diseases like diabetes.
Several medium to long-term observational studies and randomised controlled trials have reported that, in addition to inducing substantial and durable weight loss, bariatric surgery facilitates improvement or remission of metabolic complications, including type 2 diabetes, dyslipidemia (high cholesterol), and obstructive sleep apnoea in individuals with obesity. This is the basis for recent and ongoing expansion in the eligibility criteria for weight-loss surgery and the reason such procedures have been termed metabolic–bariatric surgery. Until now, data concerning the long-term health effects of metabolic–bariatric surgery have largely been limited to evidence from observational cohort studies rather than randomized controlled trials with long-term follow-up.
But a recent study has produced more robust and accurate estimates regarding the long-term effect of bariatric surgery on all-cause mortality and life expectancy, which are vital to guide policy and facilitate patient counselling.
In a meta-analysis of 174,772 individuals with 1.2 million person-years of follow-up, bariatric surgery was associated with approximately half the rate of death from any cause compared to usual care in the overall population, with more marked benefits among patients with pre-existing diabetes compared to individuals who did not have diabetes at baseline. This represents an important contribution regarding the potential public health and long-term effect of this underused weight-loss modality.
Gastric bypass surgery, banding, and sleeve gastrectomy – all methods to shrink the size of the stomach – were associated with 50–57 percent lower rates of all-cause mortality compared with matched adults with obesity in the non-surgical group.
The observation that patients with diabetes benefit more from bariatric surgery correlates with previous findings that show that raised baseline glucose and insulin concentrations were predictive of favorable treatment effects. This finding is important, with implications for future planning, development of clinical algorithms, and prioritisation of patients for metabolic–bariatric surgery. Furthermore, the median life expectancy projected in the recent study was 6.1 years longer for the metabolic–bariatric surgery group than for the control group.
Life expectancy can increase further if the BMI is higher and patients are able to lose more weight. In other words, patients with higher BMI can have up to 10-15 years longer life expectancy after undergoing metabolic surgery. This combined with newer available drugs in the treatment of diabetes and obesity can improve and eradicate co-morbidities and provide a better quality of life for people suffering from diabetes and obesity.
In conclusion, bariatric surgery is associated with substantially lower all-cause mortality rates and longer life expectancy among adults with severe obesity. Substantially greater survival benefits are also seen among people with pre-existing diabetes. As such, clinicians and policymakers should not hesitate to consider metabolic–bariatric surgery in the management of patients with obesity and type 2 diabetes.
Dr. Jaideep Raj Rao is the senior consultant surgeon at JR surgery at Mount Elizabeth Novena Hospital, Singapore. He’s a specialist in minimally invasive and robotic surgery, bariatric and metabolic surgery, as well as gastrointestinal surgery, oncology surgery, and hernia and complex abdominal wall reconstruction.