1. Global heat significantly improves the healing of chronic wounds in patients with diabetes.

The influence of local versus global heat on the healing of chronic wounds in patients with diabetes.

Diabetes Technol Ther. 2007 Dec;9(6):535-44.

Petrofsky JS, Lawson D, Suh HJ, Rossi C, Zapata K, Broadwell E, Littleton L.

Source: Department of Physical Therapy, School of Allied Health Professions, Loma Linda University, Loma Linda, California 92350, USA. jpetrofsky@llu.edu

BACKGROUND: In a previous study, it was shown that placing a subject with chronic diabetic ulcers in a warm room prior to the use of electrical stimulation dramatically increased the healing rate. However, global heating is impractical in many therapeutic environments, and therefore in the present investigation the effect of global heat versus using a local heat source to warm the wound was investigated.

METHODS: Twenty-nine male and female subjects participated in a series of experiments to determine the healing associated with electrical stimulation with the application of local heat through a heat lamp compared to global heating of the subject in a warm room. Treatment consisted of biphasic electrical stimulation at currents at 20 mA for 30 min three times per week for 4 weeks in either a 32 degrees C room or, with the application of local heat, to raise skin temperature to 37 degrees C. Skin blood flow was measured by a laser Doppler imager.

RESULTS: Blood flow increased with either local or global heating. During electrical stimulation, blood flow almost doubled on the outside and on the edge of the wound with a smaller increase in the center of the wound. However, the largest increase in blood flow was in the subjects exposed to global heating. Further, healing rates, while insignificant for subjects who did not receive electrical stimulation, showed 74.5 +/- 23.4% healing with global heat and 55.3 +/- 31.1% healing with local heat in 1 month; controls actually had a worsening of their wounds.

CONCLUSIONS: The best healing modality was global heat. However, there was still a significant advantage in healing with local heat.

2. Do Far-infrared Saunas Have Cardiovascular Benefits in People with Type 2 Diabetes?

Canadian Journal of Diabetes Volume 34, Issue 2 , Pages 113-118, 2010

Richard Beever, BSc MD CCFP CI Canadian Journal of Diabetes


OBJECTIVE: Far-infrared saunas are beneficial for the treatment of congestive heart failure, hypertension and obesity. As such, they may have a beneficial effect on cardiovascular (CV) health in those with type 2 diabetes. Our objective is to examine whether or not there are quantitative CV benefits from infrared sauna use.

METHODS: The intervention consisted of 20-minute, thrice weekly infrared sauna sessions, over a period of 3 months. The following CV risk factors were measured: weight, height, waist circumference, blood pressure (BPtru), glycated hemoglobin (A1C), fasting blood glucose and cholesterol profile. Baseline study parameters were measured within one week prior to commencing sauna sessions. Post-intervention measurements were collected between 1 and 3 days after the last sauna session.

RESULTS: Systolic blood pressure decreased by 6.4 mm Hg (124 ± 12 vs. 118 ± 15 mm Hg, 95% CI 0.01-12.71 p = 0.05), and there was a trend toward decreased waist circumference (115.0 ± 13.4 vs. 112.7 ± 11.9 cm, 95% CI 0.4-5.1 p = 0.10). All other measurements did not change significantly. There were no adverse events. Study completion rate was 75%.

CONCLUSION: Our results suggest that infrared sauna use may be beneficial for lowering blood pressure and waist circumference. Subject adherence to infrared sauna use is greater than adherence to other lifestyle interventions. The combination of favourable compliance/adherence, as well as effectiveness in improving blood pressure and possibly waist circumference, makes infrared sauna therapy an attractive lifestyle option.

3. The effects of repeated thermal therapy on quality of life in patients with type II diabetes mellitus.

J Altern Complement Med. 2010 Jun;16(6):677-81. doi: 10.1089/acm.2009.0358.

Beever R.

Source: Department of Family Medicine, University of British Columbia, British Columbia, Canada.Richard.beever@northernhealth.ca


OBJECTIVES: Decreased quality of life in diabetes is associated with poor health outcomes. Far-infrared sauna treatments improve the quality of life for those with chronic pain, chronic fatigue syndrome, depression, and congestive heart failure. The objective of this study is to determine whether far-infrared saunas have a beneficial effect on quality of life in those with type II diabetes.

DESIGN: This was a sequential, longitudinal, interrupted time series design study.

SETTING/LOCATION: The setting was Fraser Lake BC, a rural village in central British Columbia, Canada.

SUBJECTS: All patients of the Fraser Lake Community Health Center with type II diabetes were invited to participate in this study.

INTERVENTIONS: The study consisted of 20-minute, 3 times weekly infrared sauna sessions, over a period of 3 months.

OUTCOME MEASURES: To assess quality of life, subjects completed the 36-item Short-form Health Survey Version 2 (SF-36v2) questionnaire as well as “Zero-to-Ten” Visual Analogue Scales. Baseline study parameters were measured within 1 week prior to commencing sauna sessions. Postintervention measurements were collected between 1 and 3 days after the last sauna session.

RESULTS: Physical health, general health, and social functioning indices of the SF-36v2 improved. Visual Analogue Scales for stress and fatigue improved.

CONCLUSIONS: Far-infrared sauna use maybe associated with improved quality of life in people with type II diabetes mellitus. Uptake of infrared saunas use is greater than the uptake of other lifestyle interventions.

4. The effect of leg hyperthermia using far infrared rays in bedridden subjects with type 2 diabetes mellitus.

Acta Med Okayama. 2010 Apr;64(2):143-7.

Kawaura A1, Tanida N, Kamitani M, Akiyama J, Mizutani M, Tsugawa N, Okano T, Takeda E.


We examined the effect of leg hyperthermia on oxidative stress in bedridden subjects with type 2 diabetes mellitus using 15-min sessions of far infrared rays over a two-week period. Four subjects (male 1, female 3) incapacitated by a stroke were recruited for this study. All patients were admitted to Takahashi Central Hospital and ate the same hospital meals. Fasting plasma glucose, HbA1c, tumor necrosis factor (TNF)alpha, free fatty acid, leptin, adiponectin and plasma 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha) levels as a marker of oxidative stress were measured on admission, just before and 2 weeks after local heating of the leg. Results showed that plasma total 8-epi-PGF2alpha levels were decreased significantly while TNFalpha levels were increased significantly. On the other hand, glucose, HbA1c, free fatty acid, leptin and adiponectin levels were not changed during the study period.

These results suggest that repeated leg hyperthermia may protect against oxidative stress.

5. Far infra-red therapy promotes ischemia-induced angiogenesis in diabetic mice and restores high glucose-suppressed endothelial progenitor cell functions.

Cardiovasc Diabetol. 2012 Aug 15;11:99. doi: 10.1186/1475-2840-11-99.

Huang PH, Chen JW, Lin CP, Chen YH, Wang CH, Leu HB, Lin SJ.


BACKGROUND: Far infra-red (IFR) therapy was shown to exert beneficial effects in cardiovascular system, but effects of IFR on endothelial progenitor cell (EPC) and EPC-related vasculogenesis remain unclear. We hypothesized that IFR radiation can restore blood flow recovery in ischemic hindlimb in diabetic mice by enhancement of EPCs functions and homing process.

MATERIALS AND METHODS: Starting at 4 weeks after the onset of diabetes, unilateral hindlimb ischemia was induced in streptozotocin (STZ)-induced diabetic mice, which were divided into control and IFR therapy groups (n = 6 per group). The latter mice were placed in an IFR dry sauna at 34°C for 30 min once per day for 5 weeks.

RESULTS: Doppler perfusion imaging demonstrated that the ischemic limb/normal side blood perfusion ratio in the thermal therapy group was significantly increased beyond that in controls, and significantly greater capillary density was seen in the Far infra-red therapy group. Flow cytometry analysis showed impaired EPCs (Sca-1(+)/Flk-1(+)) mobilization after ischemia surgery in diabetic mice with or without IFR therapy (n = 6 per group). However, as compared to those in the control group, bone marrow-derived EPCs differentiated into endothelial cells defined as GFP(+)/CD31(+) double-positive cells were significantly increased in ischemic tissue around the vessels in diabetic mice that received Far infra-red radiation. In in-vitro studies, cultured EPCs treated with Far infra-red radiation markedly augmented high glucose-impaired EPC functions, inhibited high glucose-induced EPC senescence and reduced H(2)O(2) production. Nude mice received human EPCs treated with Far infra-red in high glucose medium showed a significant improvement in blood flow recovery in ischemic limb compared to those without Far infra-red therapy. Far infra-red therapy promoted blood flow recovery and new vessel formation in STZ-induced diabetic mice.

CONCLUSIONS: Administration of Far infra-red therapy promoted collateral flow recovery and new vessel formation in STZ-induced diabetic mice, and these beneficial effects may derive from enhancement of EPC functions and homing process.

6. The effect of type-2-diabetes-related vascular endothelial dysfunction on skin physiology and activities of daily living.

J Diabetes Sci Technol. 2011 May 1;5(3):657-67.

Petrofsky JS.


A common factor contributing to organ damage in type 2 diabetes mellitus (T2DM) is impaired tissue blood flow caused by damage to vascular endothelial cells (VECs). Damage can occur even before the clinical diagnosis of diabetes. It can be caused by both a high average blood glucose concentration and/or large daily spikes in blood glucose.

While much of the present literature focuses on the damage to vascular endothelial cells and organs from these large glucose excursions, this review will focus on the consequence of this damage, that is, how endothelial cell damage in diabetes affects normal daily activities (e.g., exercise, reaction to typical stimuli) and various treatment modalities (e.g.. contrast baths and electrical stimulation therapy).

It is important to understand the effects of vascular endothelial cells damage such as poor skin blood flow, compromised thermoregulation, and altered response to skin pressure in designing diabetes technologies as simple as heating pads and as complex as continuous glucose monitors. At the simplest level, people with diabetes have poor circulation to the skin and other organs. In the skin, even the blood flow response to locally applied pressure, such as during standing, is different than for people who do not have T2DM. Simple weight bearing on the foot can occlude the skin circulation. This makes the skin more susceptible to damage. In addition, endothelial damage has far-reaching effects on the whole body during normal activities of daily living, including an impaired response to local heat, such as hot packs and contrast baths, and higher body temperatures during whole body heating due to impaired blood flow and a reduced ability to sweat. Finally, because of multiple organ damage, people with T2DM have poor balance and gait and impaired exercise performance.