Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 1/15/2015
Publication Date: 3/28/2015
Citation: Cao, J.J. 2015. Increased circulating estradiol in mice fed a high-fat diet does not attenuate ovariectomy-induced bone structural deterioration [abstract]. Journal of Federation of American Societies for Experimental Biology. 29:755.13.
Technical Abstract: Ovariectomy-induced estrogen deficiency increases adiposity and induces substantial bone loss by increasing osteoclast activity. This study investigated whether obesity induced by a high-fat diet alter circulating estradiol levels, mitigates or exacerbates bone structure deterioration, and changes markers of bone resorption and formation in ovariectomized mice. Thirty-six female C57BL/6 mice at 4-mo-old were either sham-operated or ovariectomized and fed either a normal-fat diet (10% kcal as fat) or a high-fat diet (45% kcal as fat with extra fat from lard) ad libitum for 12 wks. Ovariectomy resulted in increased body weight, serum tartrate-resistant acid phosphatase level, and expression of cathepsin K in bone; decreased serum estradiol level; and induced significant bone loss by decreasing BV/TV, Conn.D, Tb.N, and Tb.Th while increasing Tb.Sp and SMI (P < 0.05). High-fat diet increased body weight in ovariectomized mice and slightly decreased BV/TV (P = 0.08) and SMI (P = 0.09) compared to normal-fat diet feeding. Despite having similar serum estradiol levels and higher body weight, ovariectomized mice consuming the high-fat diet had lower BV/TV, Conn.D, Tb.N, Tb.Th and greater SMI and Tb.Sp than sham mice fed the normal-fat diet. These findings indicate that increased body weight and elevated serum estradiol in ovariectomized mice in response to a high-fat diet does not protect ovariectomy-induced bone loss.