Concomitant interindividual variation in body temperature and metabolic rate

Area of Science:

• Human physiology
• Metabolic research
• Obesity studies

Background:

• Significant interindividual variations in human metabolic rate exist, independent of factors like body size, composition, age, and gender.
• While 37°C is considered the standard human body temperature set-point, metabolic rate variations suggest potential body temperature differences.

Purpose of the Study:

• To investigate potential correlations between an individual's metabolic rate and their body temperature.
• To explore if body temperature variations are linked to metabolic rate differences in humans.

Main Methods:

• Measured oral temperatures and 24-hour energy expenditure using a respiratory chamber in 23 Pima Indian men.
• Analyzed oral temperatures and adjusted metabolic rates (accounting for body size, composition, and age) in 32 Caucasian men from the Minnesota Semi-Starvation Study.

Main Results:

• Fasting oral temperatures showed significant interindividual variation beyond methodological or intraindividual fluctuations.
• Oral temperatures positively correlated with sleeping and 24-hour adjusted metabolic rates in Pima Indian men.
• Similar correlations between oral temperature and adjusted metabolic rate were observed in Caucasian men, with temperature differences persisting through nutritional changes.

Conclusions:

• Interindividual differences in human body temperature are significant and correlate with metabolic rate.
• Low body temperature and low metabolic rate may be indicative of an obesity-prone syndrome in humans.