Pearls of Wisdom: Improving Vascular Health Without Exercise
Arnold, a 48-year-old city bus driver, was recently diagnosed with type 2 diabetes mellitus. He is obese with a body mass index (BMI) of 36, smokes 2 packs of cigarettes daily since age 16, and has prehypertension.
Because his mother had diabetes and suffered multiple comorbidities, including blindness and end-stage renal disease, his diagnosis has been a bit of a wake-up call. He says that he will try to reduce his smoking and begin dieting to lower his body weight.
In the last 6 months, his BMI has not changed but his A1c (on metformin) has declined from 7.9% to 6.9%. He does not engage in any regular physical activity.
All of your suggestions to increase physical activity are met with resistance and he says the likelihood of him doing exercise is very small.
Aside from exercising, which activity might improve endothelial function in a patient with coronary risk factors?
A. Trigeminal nerve stimulation
B. Thermal therapy (dry sauna)
C. Pulsed electromagnetic field
D. Topical salicylate cream
What is the correct answer?
(Answer and discussion on next page)
Louis Kuritzky, MD, has been involved in medical education since the 1970s. Drawing upon years of clinical experience, he has crafted each year for almost 3 decades a collection of items that are often underappreciated by clinicians, yet important for patients. His “Pearls of Wisdom” as we like to call them, have been shared with primary care physicians annually in an educational presentation entitled 5TIWIKLY (“5 Things I Wish I Knew Last Year”…. or the grammatically correct, “5 Things I Wish I’d Known Last Year”).
Now, for the first time, Dr Kuritzky is sharing with the Consultant360 audience. Sign up today to receive new advice each week.
Answer: Thermal therapy (dry sauna)
Two-thirds of adult Americans are overweight or obese. Among persons with type 2 diabetes, overweight and obesity are nearly universal. Even though the benefits of exercise include improvements in glucose, better insulin sensitivity, reduced risk for cardiovascular endpoints, less risk of depression, and improved mortality, there are many individuals for whom the response is “thanks, but no thanks.”
Continued advice about the benefits of exercise and encouragement to identify physical activities that are enjoyable might ultimately win the day, but sometimes not. Is there anything we can do to encourage our confirmed couch potato patients without having to cross the threshold of exercise?
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The Research
If the data presented by Imamura et al1 is correct, maybe so. Endothelial dysfunction is fundamental to cardiovascular disease and atherosclerosis in general, and hypertension, dyslipidemia, diabetes, and cigarette smoking are all known to lead to endothelial dysfunction. Exercise improves endothelial dysfunction directly, and indirectly by improving risk factors that lead to endothelial dysfunction (e.g., obesity, insulin resistance, dysliipidemia, diabetes, depression).
Researchers performed a study to look at the effects of thermal therapy upon endothelial function. Japanese men underwent 15 minutes per day of dry sauna (60 °C) for 14 days. Endothelial function was measured by means of flow-mediated vasodilation.
First, it was noted that men with coronary risk factors had less flow mediated dilation at baseline than men without risk factors, indicative of endothelial dysfunction, despite the fact that the subjects had no manifest coronary artery disease.
Next, to show that the deficits in flow-mediated dilation were related to endothelial dysfunction (and lack of production of nitric oxide), the authors administered nitroglycerin to both groups of subjects, and found that the capacity for vasodilation was similar in response to nitroglycerin in both groups, indicating that when the endothelium is bypassed by directly supplying nitric oxide, the arterial systems of both groups were equally responsive.
The Results
After 2 weeks of daily dry sauna, flow mediated dilation improved substantially in the risk factor group, but not in controls. Overall, flow-mediated dilation improved 45%.
Thermal Rx to Improve Endothelial Function1
Additionally, it was noted that there were improvements in plasma glucose among the group who was treated with thermal therapy.
What’s the “Take Home”?
While the benefits of exercise are insufficiently capitalized upon, thermal therapy may be a beneficial option for the confirmed couch potato.
Reference:
1. Imamura M, Biro s, kihara t, et al. Repeated thermal therapy improves impaired vascular endothelial function in patients with coronary risk factors. JACC 2001;38(4):1083-1088.