Effects of maternal iron restriction in the rat on blood pressure, glucose tolerance, and serum lipids in the 3-month-old offspring.

Epidemiologic studies have demonstrated associations between low birth weight and increased rates of adult diseases such as hypertension and diabetes. Maternal iron restriction in the rat has been reported to both reduce birth weight and to elevate blood pressure at 40 days of age. The aim of the present study was to extend these findings to investigate the effects of maternal iron restriction on glucose tolerance and serum lipids, 2 important components of the metabolic syndrome, in adult offspring. Blood pressure, glucose tolerance, and serum lipids were measured in the 3-month-old offspring of iron-restricted dams. Rats were placed on control or iron-restricted diets 1 week before mating. At term, dams on the iron-restricted diet were anemic with decreased haemoglobin, red blood cell (RBC) count, hematocrit, and mean RBC volume compared with controls. Neonates from iron-restricted litters were more severely anemic than the dams. At birth, body weight was lower in the offspring of iron-restricted dams than in controls and was still decreased at 3 months of age. At this same age, systolic blood pressure was significantly elevated in the offspring of iron-restricted dams. Glucose tolerance was improved in the maternal iron-restricted group. Fasting serum insulin levels were not different between the control and maternal iron-restricted groups. Fasting serum triglyceride was decreased in the offspring of iron-restricted dams compared with controls. Fasting serum cholesterol and free fatty acid concentrations were similar in both groups. These results suggest that maternal iron restriction has long-term effects on physiology and metabolism in the offspring. Some of these findings are comparable to those reported for the maternal protein-restriction model. It is thus speculated that the long-term effects of maternal dietary restriction may result from common fetal metabolic responses to this restriction. Copyright 2001 by W.B. Saunders Company.