Osteopenia due to chronic alcohol consumption by young actively growing rats is not completely reversible

Our project was conducted to determine if the deleterious effects of chronic alcohol consumption on growing bone are reversible if the adolescent stops drinking. Four-week old, female, Sprague-Dawley rats were housed and maintained in an AAALAC-accredited facility. Six animals each were placed on alcohol-fed (35% ethanol-derived calories), pair-fed or chow-fed diets for 2 or 4 weeks. A recovery group of six animals was alcohol-fed for 2 weeks followed by an additional 2 weeks of chow feeding. This group was pair-fed to an additional group of six animals that received liquid diet, pair fed to the recovery group for 2 weeks followed by 2 weeks on a pair-fed chow diet. Blood alcohol concentrations averaged 309 +/- 9 mg/dl. Morphological parameters of the femur, such as length, diameter, and volume were smaller in alcohol treated animals at both 2 and 4 weeks of feeding. Femur length and volume of recovery alcohol-fed animals were more than either 2- or 4-week alcohol-fed animals, but they were not as great as the same-age 4-week pair-fed or chow-fed animals. Diameter was similar to the 4-week alcohol-fed, but less than the chow-fed. Femur density was reduced at all time periods in the alcohol-fed animals. The recovery alcohol-fed animals had greater density than the 2-week alcohol, but not the 4-week alcohol-fed animals. They did not, however, reach 4-week chow- or pair-fed levels. Tibia BV/TV was reduced in the 2- and 4-week alcohol- and pair-fed animals. BV/TV was greater in the recovery animals than either 2- or 4-week alcohols, but not as great as the chow-fed animals. At 2 weeks, calorie deprivation caused a reduction in insulin-like growth factor-1 (IGF-1) that was reduced even more by alcohol. By 4 weeks, the calorie deprivation was no longer seen, but alcohol continued to reduce the values. Two weeks of alcohol followed by 2 weeks of chow diet returned the IGF-1 values to almost normal, but significantly different levels. The apparent improvement was probably due to continued growth of the young bones and not a regaining of bone lost during alcohol consumption.