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Increased Circulating Estradiol in Mice Fed a High‐Fat Diet does not Attenuate Ovariectomy‐Induced Bone Structural Deterioration
Author(s) -
Cao Jay
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.755.13
Subject(s) - ovariectomized rat , endocrinology , medicine , estrogen , bone resorption , osteoclast , cathepsin k , obesity , osteoporosis , leptin , chemistry , receptor
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.