New research presented at this year’s European Congress on Obesity (ECO) in Venice, Italy (May 12-15), identifies the optimal weight range for adults with type 2 diabetes to minimize the risk of death from any cardiovascular disease, including heart failure, heart disease, stroke and chronic kidney disease.
The findings, based on health data from UK Biobank, show that for adults aged 65 and under, maintaining a body mass index (BMI) within the normal range of 23–25 kg/m² was associated with the lowest risk of death from cardiovascular disease . But for people over 65, being moderately overweight with a BMI of 26–28 kg/m² had the lowest risk.
Maintaining a healthy weight is crucial to reducing the risk of cardiovascular disease, especially for people with type 2 diabetes who are predisposed to cardiovascular disease and death. However, it is unclear whether the optimal BMI range for people with type 2 diabetes varies by age.
To address these knowledge gaps, researchers investigated age differences in the association between BMI and risk of cardiovascular death in 22,874 UK Biobank participants with a prior diagnosis of type 2 diabetes at the time of enrollment between 2006 and 2010. Patients with prior cardiovascular disease was not ruled out.
The average age of all participants was 59 years, and about 59% were women. Their cardiovascular health was tracked, using linked health records, for nearly 13 years during which 891 participants died of cardiovascular disease.
The researchers analyzed data in two age groups—elderly (over 65) and middle-aged (age 65 or younger)—and assessed the relationship between variables such as BMI, waist circumference, and waist-to-height ratio and cardiovascular risk. of death.
The optimal BMI cut-off point was also calculated in different age groups, and the findings were adjusted for traditional cardiometabolic risk factors and other factors associated with adverse cardiovascular outcomes, such as age, gender, smoking history, alcohol consumption, level of physical activity, and history of cardiovascular disease .
The analyzes found that in the middle-aged group, having a BMI in the overweight range (25 kg/m² to 29.9 kg/m²) was associated with a 13% greater risk of death from cardiovascular disease than those with a BMI in the normal range (less than 25.0 kg/m²).
However, in the elderly group, having a BMI in the overweight range (25 kg/m² to 29.9 kg/m²) was associated with an 18% lower risk of death compared with having a BMI in the normal range (less than 25.0 kg/m² m²).
The relationship between BMI and risk of cardiovascular death showed a U-shaped pattern, even after stratifying by age, so the optimal BMI cut-off point was different in the older and middle-aged groups. For the middle-aged group, the optimal BMI cut-off was 24 kg/m², while for the elderly group it was 27 kg/m². Consequently, individualized treatment plans can be developed in clinical settings by tailoring recommendations to different age groups.
The researchers also found a positive relationship between waist circumference and waist-to-height ratio and the risk of cardiovascular death. As waist circumference increased, so did the risk of cardiovascular death. When the study population was divided into older and middle-aged categories, this upward trend remained constant. Similar patterns were observed for waist-to-height ratio. However, no significant BMI cut-off point was identified.
Importantly, we demonstrate that optimal BMI for individuals with type 2 diabetes varies with age, independent of traditional cardiometabolic risk factors. Our findings suggest that for older people who are moderately overweight but not obese, maintaining rather than losing weight may be a more practical way to reduce the risk of death from CVD.”
Dr Shaoyong Xu, main author from Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, China;
He adds, “Our findings also suggest that obesity may offer some protection against fatal diseases to some extent. Possible biological mechanisms explaining this ‘obesity survival paradox’ in the elderly may be related to a lower rate of bone loss, the which reduces the effects of fall and trauma episodes and greater nutritional reserves to deal with periods of acute stress.”
The authors say that in the future, measures of central obesity, such as waist circumference, will be used to further refine risk.
This is an observational study, and therefore, cannot determine cause. And the researchers acknowledge several limitations to their findings, including small numbers of cardiovascular deaths and no information on the type of cardiovascular disease or specific treatments. They also note that most of the participants in the UK Biobank study are White, so the findings may not apply to people of other ethnicities. Also, the nature of the cohort study may introduce potential misclassification errors that could partially influence the conclusions because anthropometric measurements were assessed only at the beginning of the study and body weight may change during the follow-up period.
