Cause and Effect, Waist Circumference and Health Costs

OMG. How can we possibly cope with the costs of treating obesity with these expensive new obesity meds? This question seems to be on the lips of many who pay for health plans. But a new study in Nature Communications turns that question on its head. How can we afford to continue withholding effective treatment for obesity? That might be the right question to ask because it turns out that waist circumference has the highest causal effect on total annual health costs of 15 factors analyzed in the new study.

For every standard deviation of increase in waist circumference, health costs go up by 23%.

Mendelian Randomization to Estimate Causal Effects

Jiwoo Lee and colleagues used Mendelian randomization to estimate the causal effects of 15 different risk factors on total annual healthcare costs. The essence of Mendelian randomization is to use measured variation in genes that influence a modifiable risk factor to estimate the causal effect of that risk factor on an outcome. In this study, the outcome was annual health costs.

Waist circumference, body mass index, and systolic blood pressure had a significant causal effect on health costs. Serum albumin, C-reactive protein, and vitamin D were three factors for which no effect was found. For some of the others, results were less clear.

Of course, estimation of causal effects on something like health costs is no simple task. For this task, Mendelian randomization does not yield magical answers. The authors go into some detail on the limitations of their methods. Nonetheless, this study offers important insights.

At the top of that list of insights is the conclusion that

“Increased waist circumference is a major contributor to annual total healthcare costs and more attention may be given to WC screening, surveillance, and mitigation.”

The Non-Trivial Global Costs of Obesity

It should not be a surprise that obesity is costly, and it’s growing. It will add up to more than four trillion dollars annually by the middle of the next decade. But in the absence of effective strategies for prevention or treatment, policymakers and payers have grown used to neglecting it.

Now, with growing options for more effective treatment, that calculus is changing. Given that the costs are so great and effective treatment is possible, denying access to effective obesity care is fiscally unsustainable. Business analysts are starting to see broad utilization of advanced obesity medicines as inevitable. Saying she would never dismiss the capacity of America to make bad decisions about healthcare, Bloomberg Executive Editor Tracy Alloway recently explained the case for broader utilization:

“At some point it might be cheaper for an insurance company to just provide these drugs rather than treat someone for diabetes or heart problems or sleep apnea or whatever else for the rest of their lives.”

As the costs of untreated obesity mount, this reality becomes ever more obvious.

Click here for the new study in Nature Communication and here for the discussion about broader utilization of obesity treatment with Tracy Alloway.

Economic Gears, photograph by Ted Kyle / ConscienHealth

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September 17, 2023