1. Department of Nursing, College of Medicine & Nursing, Hung Kuang University, Taichung, Taiwan;
2. School of Medicine, Chung Shan Medical University, Taichung, Taiwan;
3. Department of Orthopedic Surgery, Chung Shan Medical University, Taichung 402, Taiwan;
4. Center for Molecular Medicine, China Medical University Hospital, Taichung, Taiwan;
5. Department of Laboratory Medicine, Kuang Tien General Hospital, Taichung, Taiwan;
6. Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan;
7. Emergency department and center of Hyperbaric Oxygen Therapy, Tungs' Taichung MetroHarbor Hospital, Taichung Taiwan;
8. Department of Psychiatry, Chung Shan Medical Hospital, Taichung,Taiwan;
9. Graduate Institute of Cancer Biology, China Medical University, Taichung, Taiwan;
10. Institute of Biochemistry, Microbiology and Immunology, Medical College, Chung-Shan Medical University, Taichung, Taiwan;
11. Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, Taiwan;
Objectives: Menopausal transition with declining estrogen levels significantly affects the physiological properties of women and consequently contributes to a series of medical conditions, including obesity. Obesity is a crucial risk factor associated with cardiovascular diseases, diabetes mellitus, and breast cancer. Increasing dietary protein content improves satiety and energy expenditure. Thus, we hypothesize that supplementing with collagen, a common dietary protein, may alleviate menopause-induced obesity.
Methods: We used ovariectomized (OVX) rats to mimic a menopausal human. The body weight of OVX rats significantly increased compared with that of sham-operated rats (P<0.05), but uterus weight was decreased. Adipocyte size in perigonadal adipose tissue also increased (P<0.05).
Results: By contrast, OVX rats supplemented with aqueous collagen hydrolysate (2.5 mg/mL) exhibited significant attenuation in body weight gain and adipocyte enlargement (P<0.05), but insignificant change in uterus weight. Further investigation indicated that collagen hydrolysate supplementation insignificantly affected the levels of dorsal fat, serum total cholesterol, and serum triacylglycerol. Levels of serum biochemical factors, calcium, phosphorus, and glucose were also insignificantly altered by collagen hydrolysate supplementation.
Conclusion: Collagen hydrolysate supplementation reduced body weight gain and adipocyte enlargement in response to ovariectomy but slightly affected blood lipids, calcium, and glucose in both sham-operated and OVX rats. Collagen hydrolysate supplementation is beneficial in ameliorating estrogen deficiency-induced obesity and its associated risk factors.
Keywords: Collagen, Obesity, estrogen deficiency