Adolescence is a critical period for skeletal development during which peak bone mass is acquired. Binge drinking, a prevalent form of alcohol misuse among adolescents, has been associated with impaired bone growth and reduced skeletal integrity. Although alcohol-induced skeletal alterations have been widely studied in weight-bearing bones such as the femur and tibia, its effects on the humerus and the potential for skeletal recovery following abstinence remain poorly understood. This study investigated the effects of binge drinking on adolescent humeral structure, strength, and development, along with recovery potential after a period of alcohol abstinence, using a Sprague Dawley rat model. Animals were divided into two experimental groups: Group 1 (four weeks of alcohol exposure) and Group 2 (four weeks of alcohol exposure followed by 30 days of abstinence). Each group consisted of an alcohol-exposed (A) and a pair-fed control (B) subgroup, with 12 rats per group (6 males and 6 females). Alcohol-exposed groups received a 3 g/kg dose of a 20 % alcohol solution three times per week, and pair-fed control groups received an isocaloric equivalent of maltodextrin. Humeral microarchitecture was assessed using micro-computed tomography (3DμCT), biomechanical properties were evaluated using three- point bending, and growth plate proliferation was assessed using Ki-67 immunohistochemistry. Alcohol administration produced blood alcohol concentrations consistent with binge exposure (141–164 mg/dL). After four weeks of exposure, females demonstrated a modest reduction in humeral weight compared with controls (p = 0.045). Pronounced sex differences were observed across osteometric parameters, with males exhibiting greater humeral weight, length, and bicondylar breadth (p < 0.001). 3DμCT analysis revealed higher bone volume fraction in female distal epiphyses (p = 0.009). Following abstinence, alcohol-exposed males exhibited increased trabecular numbers and reduced trabecular separation (p < 0.05), while biomechanical testing demonstrated reduced fracture times in female humeri. These findings suggest that adolescent binge drinking may induce persistent, sex-specific changes in humeral microarchitecture and mechanical properties that are not fully reversed following short-term abstinence.

KEY WORDS: Adolescent; Alcohol; Binge Drinking; Humerus.

RAKGOATHE, R.; MALUNGO, I. & BHIKA, A. The impact of binge alcohol consumption on the developing adolescent Sprague Dawley rat humerus. Int. J. Morphol., 44(4):1461-1468, 2026.