Thermal stress and diabetic complications

Area of Science:

• Biochemistry
• Endocrinology
• Environmental Health

Background:

• Erythrocyte aldose reductase plays a role in glucose metabolism.
• Elevated aldose reductase activity is linked to diabetic complications.
• Environmental factors like temperature can influence physiological processes.

Purpose of the Study:

• To compare erythrocyte aldose reductase activity in normal subjects and diabetic patients.
• To investigate the effect of varying water temperatures on enzyme activity.
• To assess the potential impact of heat stress on diabetic complications.

Main Methods:

• Enzyme activity assays were performed on erythrocytes from 34 normal subjects and 45 diabetic patients.
• Subjects were exposed to water immersion at 25, 39, and 42 degrees C for 10 minutes.
• Enzyme activity was correlated with Hemoglobin A1 (HbA1) and fasting plasma glucose levels.

Main Results:

• Diabetic patients showed significantly higher basal erythrocyte aldose reductase activity compared to normal controls (2.07 vs 1.11 U/g Hb, P < 0.0001).
• Enzyme activity correlated positively with HbA1 concentrations (P < 0.01) but not fasting plasma glucose.
• Immersion at 42 degrees C increased activity by 37.6% (P < 0.01), while 39 degrees C and 25 degrees C decreased it by 52.2% (P < 0.005) and 47.0% (P < 0.05), respectively.

Conclusions:

• Elevated erythrocyte aldose reductase activity in diabetics may contribute to complications.
• Heat stress significantly modulates aldose reductase activity, potentially exacerbating diabetic conditions.
• Exposure to hot environments is not advisable for individuals with diabetes.