Alcoholism: A systemic proinflammatory condition

Table 2 Main factors involved in ethanol-associated osteopenia

Factors	Main mechanism(s) involved
Direct effect of ethanol	Direct effect on osteoblast function (oxidative damage). Possible effect on bone resorption (cytokines)
Liver disease	Decreased absorption of proteins, calcium, vitamin D, nutrients in general
	Altered hormonal profile (altered IGF-1, vitamin D, gonadal hormones)
Chronic pancreatitis	Altered absorption. Malnutrition
Malnutrition	Decreased osteoid synthesis. Decreased IGF-1 levels. Altered nutrient intake. Altered absorption. Increased cytokine levels?
Alcoholic hypogonadism	Altered trophic effect on bone and muscle
Alcoholic myopathy/neuropathy	Altered trophic effect on bone (probably via Wnt β catenin pathway)
Iron excess (increased absorption)	Interference with osteoblast function
Zinc deficiency (malnutrition; alcohol?)	Possibly, defective protein synthesis
Cytokines (IL-6; TNF-α)	Possibly, increased bone resorption
Lifestyle	Trauma. Bone fractures. Impaired nutrient intake

IGF: Insulin-like growth factor; TNF: Tumor necrosis factor; IL: Interleukin.