The effect of protein-energy malnutrition on development of hypertension, glucose metabolism and insulin sensitivity in genetically hypertensive rats.

BACKGROUND AND AIM

The objective of the study was to elucidate the beneficial effect of protein-energy malnutrition (PEM) on development of hypertension in a genetic model of salt-sensitive hypertensive rats by evaluation of glucose metabolism and insulin sensitivity.

METHODS AND RESULTS

Dahl Salt-Resistant (DSR) and Salt-Sensitive (DSS) rats were subjected to a low-protein (LP) diet (protein--5.8%, sucrose--51% and fat--7%) for 2 months. Two DSR and DSS groups on a normal protein (NP) diet and pair-fed animals served as controls. Glucose metabolism and insulin sensitivity were assessed by the euglycemic clamp technique. The results showed: DSR rats on the LP diet displayed significantly decreased systolic blood pressure (SBP), and decreased plasma insulin and blood glucose levels with significantly increased overall peripheral glucose utilization and glucose clearance. The pair-fed DSR followed the pattern of DSR on the LP diet with decreased SBP. The most interesting SBP results were shown in the pair-fed DSS rats, which despite low food intake and body weight gain developed hypertension similar to DSS on the NP diet. DSS rats on the LP diet also failed to develop hypertension by contrast with the DSS rats on the NP diet and pair-fed DSS rats. DSS rats on the LP diet significantly improved their insulin sensitivity to the level of DSR rats with significantly increased glucose utilization and glucose clearance. In both DSR and DSS groups on LP and pair-fed, a significant increase of heart rate was found. This was more pronounced in the DSS groups.

CONCLUSIONS

The beneficial effect of PEM on development of hypertension is attributed to increased glucose utilisation and improved insulin sensitivity.