Seven doctors look after different parts of my body. I have a general practitioner who functions as a gatekeeper for my health insurance plan. Like many people with diabetes, there’s an endocrinologist. I also regularly see an ophthalmologist, a dermatologist, a urologist, a podiatrist, and a dentist.
Does sitting in a hot tub simulate exercise?
When one of them recently recommended that I take regular hot baths to treat a condition unrelated to my diabetes, the first thing I told him was that I couldn’t. That's because we use our bathtub to keep the kitty litter box. I do keep clean, but I always use a shower.
After I left his office, I began to think. Ever since leaving the Santa Barbara area eight years ago I have missed the plentiful hot tubs, Jacuzzis, and hot springs in that area. The Santa Cruz area, where I live now, is wonderful, but is not as tuned into hot water.
Four years ago when we moved to our home in Aptos, a suburb of Santa Cruz, I priced hot tubs. However, I wasn’t willing to spend the $10,000 I would have needed for the redwood tub I wanted.
Finally, I remembered that there is an the athletic club a couple of miles down the road that had hot tubs. I am not the sort of person who works out in a gym, so I had never considered it before. However, when I toured the facility, I discovered that they had a great outdoor co-ed hot tub, a lovely men’s hot tub off the men’s locker room, and presumably a similar women’s hot tub. The club carefully maintains the hot tubs and heats all of them to a perfect 104° F.
I signed up immediately and have begun to use two of the hot tubs regularly to treat my condition and for pure enjoyment at the same time. Except for the outdoor swimming pool, I still haven’t begun to make use of the many other facilities at my club.
As much as I enjoy my now regular dips in the tub, I have long been aware that they are controversial. Consequently, I researched the literature.
Surprisingly, a MEDLINE search revealed that only one professional journal has ever reported on hot tubs and diabetes (the search turned up three other articles in different journals, but they had little relevance to the issue at hand). The prestigious New England Journal of Medicine carried articles on hot tubs and diabetes in one 1999 issue and two issues during 2000. Only one of these, however, reported a study. The others were commentary.
None of these articles have on-line abstracts. However, the articles were readily available at the college library, which happens to be across the street from my athletic club and its hot tubs.
The study, led and reported by Philip L. Hooper, M.D., of the McKee Medical Center in Loveland, Colorado, was a small one, but its results were extremely promising. Their thesis was that exercise is effective for people with type 2 diabetes. They wondered if sitting in a hot tub with water up to their shoulders would simulate the benefits of exercise for their patients.
Eight patients participated. They used the hot tub for half an hour a day, six days a week, for three weeks. Water temperature ranged from 100° F to 105.8° F. Diet, exercise routines, and medication were stable for eight weeks before and during the test period, although one participant had to reduce his insulin dose by 18 percent to prevent hypoglycemic reactions.
After three weeks the mean weight of the patients had decreased 3.7 pounds. Mean fasting plasma glucose level decreased from 182 mg/dl to 159 mg/dl. Their mean A1c levels dropped from 11.3 to 10.3. As the study progressed, the participants reported improved sleep and an increased general sense of well-being.
How could hot tub therapy work so well? Dr. Hooper theorizes that the benefits could result from increased blood flow to skeletal muscles.
Neil H. Cox, F.R.C.P., of the Cumberland Infirmary, Carlisle, U.K., and Richard K. Bernstein, M.D., director of the New York Diabetes Center in Mamaroneck, New York, subsequently voiced concerns. The reply by Dr. Hooper suggests at least three caveats for hot tub therapy.
Dr. Cox noted that water infected with pseudomonas bacteria could cause an inflammation of the hair follicles. I remembered that widespread infection of natural hot springs in Southern California led me to stop bathing there long before I moved north. The key, as Dr. Hooper points out, is to monitor the pH of the water, water filtration, and the balance of chemical disinfectants.
Dr. Bernstein expressed his concern about exposure to hot water by people with diabetes who have decreased blood supply in their feet and legs. In addition, people who have diabetic neuropathy may be burned without feeling it.
Dr. Hooper responded that he and his colleagues agree that hot tub therapy is not recommended for people with decreased blood supply in their feet and legs. People with diabetic neuropathy should rely on thermometer readings rather than their subjective sense of heat.
“Interestingly,” Dr. Hooper added, “three patients in our study commented that their feet felt better after three weeks of hot-tub exposure, with improved sensation and a decrease in the formation of calluses.”
If you choose to use hot-tub therapy, make sure the facility is clean, and that you have adequate circulation in your feet and legs. Be especially careful if you have neuropathy. Otherwise, it seems that hot tubs have a lot to offer, especially for those of us who can’t—or won’t—exercise.
After writing this article, several correspondents have told me that people with hypertension (high blood pressure) should not use hot tubs. In fact, many facilities have such warning signs. Since most people with diabetes have high blood pressure, if this is a fact, it could be most relevant.
However, one correspondent, Cathy Storey in Edmonton, Alberta, Canada, brought a study of 23 people with normal blood pressure and 21 whose blood pressure was too high. For both groups systolic blood pressure falls by about 20 percent during 10 minutes of hot tub bathing. Earlier studies indicate this isn’t a problem and that hot tubs are safe for people whether they have high blood pressure or not.
Hooper PL. Hot-tub therapy for type 2 diabetes mellitus. N Engl J Med 1999 Sep 16;341(12):924-5.
Bernstein RK. Hot-tub therapy for type 2 diabetes mellitus. N Engl J Med 2000 Jan 20;342(3);218; author reply 218-9.
Cox NH. Hot-tub therapy for type 2 diabetes mellitus. N Engl J Med 2000 Jan 20:342(3);218; author reply, 218-9.
Correction. Hot-Tub Therapy for Type 2 diabetes mellitus. N Engl J Med 2000 Jul 20; 343(3);228.
Shin, Tae Won, Merne Wilson, and Thomas W. Wilson. Real Risks or Made-up Myths? The Truth About Hot Tubs and Saunas for Hypertensive Patients. Hypertension Canada 2003 Mar; 74;6 online at http://www.stacommunications.com/customcomm/Back-issue_pages/Hyp_Can/hypcanPDFs/eng/2003/HypCanMarch2003e.pdf
This article originally appeared on Mendosa.com on September 26, 2003.
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