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In a nutshell
- A study of over 6,600 Americans with diabetes found that having a moderately larger waist circumference was associated with better survival rates – up to 107 cm (42 inches) for women and 89 cm (35 inches) for men
- The relationship between waist size and mortality followed different patterns by gender: a U-shaped curve for women (higher risk at both low and high measurements) and a J-shaped curve for men (risk increasing more sharply at higher measurements)
- These findings challenge traditional medical guidance about waist circumference in diabetes patients and suggest that optimal measurements may need to be personalized based on factors like gender rather than following universal targets
JIANGSU, China — Most health professionals would likely raise an eyebrow at the suggestion that a larger waist circumference might benefit some diabetes patients. Yet that’s exactly what researchers discovered when they analyzed survival rates among more than 6,600 American adults with diabetes, finding that the relationship between waist size and mortality follows unexpected patterns that vary significantly between men and women.
Medical professionals have long preached the dangers of excess belly fat, particularly for people with diabetes. However, follows distinct U-shaped and J-shaped patterns for women and men respectively, suggesting that both too little and too much belly fat could be problematic.
Researchers from Northern Jiangsu People’s Hospital in China analyzed data from the National Health and Nutrition Examination Survey (NHANES), a massive health study of Americans conducted between 2003 and 2018. They tracked the survival outcomes of 3,151 women and 3,473 men with diabetes, following them for roughly six to seven years on average.
The findings challenge conventional wisdom: women with diabetes actually showed the lowest mortality risk when their waist circumference hit 107 centimeters (about 42 inches), well above what’s typically considered healthy. For men, the sweet spot was 89 centimeters (around 35 inches), closer to traditional recommendations but still surprising in its implications.
The relationship manifested differently between the sexes. For women, the association between waist size and mortality formed a U-shaped curve – meaning death rates were higher among those with both smaller and larger waists than the optimal point. Men showed a J-shaped pattern, with mortality risk rising more steeply as waist sizes increased beyond the optimal point.
This phenomenon, dubbed the “obesity paradox,” isn’t entirely new to medical research. Similar patterns have been observed with body mass index (BMI) in various populations. However, this study is among the first to demonstrate it specifically with waist circumference in people with diabetes.
The findings were consistent across different causes of death. Whether looking at overall mortality or deaths specifically from cardiovascular disease, the patterns held steady. For every centimeter increase in waist size below the optimal point, women saw their mortality risk decrease by 3%, while men saw a 6% reduction. Above these thresholds, each additional centimeter increased mortality risk by 4% in women and 3% in men.
What makes these findings particularly intriguing is their persistence even after researchers accounted for numerous other factors that could influence survival, including age, education, ethnicity, smoking status, drinking habits, physical activity, and various health conditions.
While these findings might seem counterintuitive, they align with a growing body of research suggesting that optimal health parameters might vary more widely between individuals than previously thought. For diabetes patients and their healthcare providers, this study offers compelling evidence that when it comes to waist circumference, the relationship with survival is more complex than simply “less is more.”
Paper Summary
Methodology
The researchers utilized data from NHANES, which employs a complex sampling strategy to ensure its findings represent the U.S. population. They included adults aged 18 and older who had diabetes, as confirmed by blood tests or self-reported diagnosis. Waist circumference was measured using standardized methods, and participants were followed until December 2019 or death. The team used sophisticated statistical models to analyze the relationship between waist size and mortality, adjusting for numerous potential confounding factors.
Results
The study found distinct patterns for men and women. Women showed lowest mortality risk at a waist circumference of 107 cm, with risk increasing both above and below this point. Men’s lowest risk occurred at 89 cm, with risk increasing more sharply above this point. These patterns remained consistent whether looking at all-cause mortality or cardiovascular-specific deaths.
Limitations
The researchers acknowledge several limitations. The observational nature of the study means they can’t prove cause-and-effect relationships. Waist measurements were only taken at the beginning of the study, not accounting for changes over time. The study population was specifically American, so findings might not apply to other populations.
Discussion and Takeaways
The research suggests that optimal waist circumference might be higher than currently recommended, particularly for women with diabetes. However, the authors caution against promoting specific waist size targets, emphasizing instead the need for individualized approaches to health management. The findings also highlight the importance of considering gender differences in health recommendations.
Funding and Disclosures
The study was funded by grants from the National Key R&D Program and the M.D. startup foundation of Northern Jiangsu People’s Hospital. One author serves on the journal’s editorial board, but no other conflicts of interest were reported.
Publication Information
This research was published in Exploratory Research and Hypothesis in Medicine, 2024, DOI: 10.14218/ERHM.2024.00400. The study represents a collaboration between researchers from multiple institutions in Yangzhou, Jiangsu, China.
