Bodyweight Variability May Increase Risk for Major CV Events in Type 2 Diabetes Patients: New Study

Loss or gain of 5% or more bodyweight during a 2-year period increased risk for major CV events.

A gain or loss of more than 5% bodyweight over a 2-year period was associated with an increased risk for major adverse cardiovascular events among more than 1.5 million adults with type 2 diabetes (T2D) according to new findings from a group of researchers in South Korea.

The strongest association, as reported in Diabetes Care, was seen between heart failure (HF) risk and participants who either lost or gained up to 10% of their baseline bodyweight.

Senior author Hyung-Kwan Kim, MD, PhD, of the Seoul National University Hospital, Republic of Korea, and colleagues cite as background for the study the still “elusive” association between weight loss and specific cardiovascular disease events including HF, myocardial infarction (MI), ischemic stroke (IS), atrial fibrillation (AF), and all-cause death in patients with T2D, even though the benefits of weight loss on overall metabolic profiles in this population are well known.

For the longitudinal study, Kim et al used the Korean National Health Insurance Service database to screen patients with general health check-ups twice in a 2-year period between 2009 and 2011. The investigators identified 1 522 241 adults who had T2D and no history of major cardiovascular events. Average cohort age was 56.3 years and 63.7% were men.

At the end of a median 7-year follow up, the researchers stratified patients according to the magnitude of bodyweight change between the 2 documented general health visits: weight loss of ≤10%, 10% to ≤ 5%, 5% to ≤5% and weight gain of 5% to ≤10% and >10%.

They found that most of the participants didn’t gain or lose more than 5% of their baseline weight during the 2-year period. However, 8% of patients gained 5-10% and 2% gained still more. When they looked at weight loss, 12% of the group lost 5-10% and 3% lost >10%. At baseline, BMI in the group with the most weight loss was 22/7 kg/m² and 26.2 kg/m² in the group with the greatest weight gain.

Incident cardiovascular events during follow-up were MI 32 106, IS 44 406, AF 34 953, HF 68 745, and all-cause deaths 84 635.

The researchers found the strongest associations were for HF, with adjusted incidence rates per 1000-person years of:

• 10.73 loss of >10% bodyweight
• 7.95 loss of 5-10%
• 6.44 weight remained stable
• 7.00 gain of 5-10% 
• 8.77 gain of >10%

After multivariable adjustment, there was a significant increase in risk for HF among people who lost or gained at least 5% of baseline weight vs those whose weight was stable; hazard ratios ranged from 1.13 to 1.41, according to the study.

A similar pattern of increased risk was seen during a 2-year interval for the other CV events of interest, MI, IS, and AF, with most of the associations reaching statistical significance.

Likewise, increased risk for all-cause mortality was seen with a loss or gain of ≥5% of baseline bodyweight with reported adjusted incidence rates of 19.04, 10.80, 7.35, 8.62, and 12.09 per 1000 person–years across groups from >10% weight loss to >10% weight gain.

Relative to participants in the group whose weight remained stable, adjusted hazard ratios for mortality ranged from 1.23 to 1.87.

The authors cite research that shows variability in bodyweight alone linked to an increased risk for CV events and the also hypothesize a possible association between weight-loss induced frailty and increased risk for hypoglycemia as a result of reduced lean mass.

They write in their conclusion, “Taken together, the longer-term association between weight loss and cardiovascular events in patients with [type 2 diabetes] is possibly more complicated than we have expected based only on simple metabolic profile improvement with relatively limited follow-up duration.”

They also emphasize that the study design did not allow distinction between intentional and unintentional weight loss and that underlying morbidity could cause the latter. And so, they add, clinical weight loss in patients with T2D “may not necessarily reflect metabolic improvement.”

Reference: Park CS, Choi Y-J, Rhee T-M, et al. U-shaped associations between body weight changes and major cardiovascular events I type 2 diabetes mellitus: a longitudinal follow-up study of over 1.5 million nationwide cohort. Diabetes Care. Published online March 9, 2022.