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 chroni c alcohol consumption on growing bone are reversible if the adolescent stop s drinking. Four-week old, female, Sprague-Dawley rats were housed and main tained in an AAALAC-accredited facility. Six animals each were placed on al cohol-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 fol lowed 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 t he recovery group for 2 weeks followed by 2 weeks on a pair-fed chow diet, Blood alcohol concentrations averaged 309 +/- 9 mg/dl, Morphological parame ters of the femur, such as length, diameter, and volume were smaller in alc ohol treated animals at both 2 and 4 weeks of feeding. Femur length and vol ume of recovery alcohol-fed animals were more than either 2- or 4-week alco hol-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 l ess 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 n ot, 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 t he 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 insulinlike growth factor-1 (IGF-1) that was reduced even more by alcohol. By 4 weeks, the calorie deprivation was no longer seen, but alcohol contin ued 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 differen t levels. The apparent improvement was probably due to continued growth of the young bones and not a regaining of bone lost during alcohol consumption .