Magnesium deficiency-induced anorexia in hyperphagic obese Zucker rats

Area of Science:

• Nutritional Science
• Metabolic Disorders
• Cardiovascular Health

Background:

• Diabetes mellitus is a primary cause of hypomagnesemia and magnesium depletion in clinical practice.
• Obese Zucker rats serve as a relevant model for non-insulin-dependent type II diabetes, with lean Zucker rats as controls.

Purpose of the Study:

• To investigate the impact of dietary magnesium deficiency on obese Zucker rats.
• To understand the relationship between magnesium depletion, obesity, and potential cardiac implications in this disease model.

Main Methods:

• Obese Zucker rats were fed a diet deficient in magnesium (25% of requirement) for 125 days.
• Control groups received magnesium-fortified water or were pair-fed with lean, magnesium-deficient controls.
• Measurements included feed consumption, body weight, blood glucose, and tissue magnesium and calcium levels.

Main Results:

• Mg-deficient obese rats consumed 50% less food and gained 50% less weight than controls, with effects not fully reversible.
• Heart muscle showed decreased magnesium and increased calcium in deficient rats, indicating potential cardiac risk.
• Pair-feeding prevented obesity development in Mg-deficient rats, and blood glucose remained unaffected.

Conclusions:

• Dietary magnesium deficiency significantly impacts weight gain and food consumption in obese Zucker rats.
• Magnesium depletion is associated with altered cardiac muscle composition (reduced Mg, increased Ca), suggesting increased cardiac risk.
• Further research is needed to explore marginal magnesium deficiency's role in obesity pathogenesis without inducing anorexia.