Organ weight changes associated with body mass index determined from a medical autopsy population

Existing organ weight charts used by pathologists for patients undergoing medical autopsy do not illustrate the effect of obesity and age on organ weights among a general population of older individuals with multiple comorbidities.

We retrospectively reviewed 300 medical autopsy reports to extract data to analyze the effect of obesity and age on organ weights.

In both men and women, there were statistically significant increases in organ weights with body mass index (BMI) but decreases with age for liver, spleen, and kidneys. In men, increased age was associated with increased left ventricular wall thickness, whereas increased BMI was associated with increased heart weight. In women, only BMI was associated with changes in all 3 anatomic cardiac parameters (heart weight and thickness of the right and left ventricular walls). Age effects were not observed for heart parameters in women. Thyroid weight increased with BMI in men but not in women.

The findings demonstrate changes in organ weights/sizes with obesity and age in a population of patients with multiple comorbidities. The differential effects of age and BMI on the heart between men and women raise the possibility that increased BMI in women may have a greater impact on cardiovascular causes of death than that in men.