Low Protein Intake Magnifies Detrimental Effects of Ovariectomy and Vitamin D on Bone

作者：Marotte Clarisa; Gonzales Chaves Macarena M S; Pellegrini Gretel G; Friedman Silvia M; Lifshitz Fima; Mandalunis Patricia; Zeni Susana N^*

来源：Calcified Tissue International, 2013, 93(2): 184-192.

DOI：10.1007/s00223-013-9740-8

• Bisphosphonate
• Bone
• Low protein intake
• Rats
• Vitamin D insufficiency

Protein-induced changes in bone and calcium homeostasis could potentially be greater in the elderly and in women at risk for osteoporosis. We hypothesize that a low protein intake would magnify the negative changes in bone metabolism seen in vitamin D (vitD) insufficiency and/or estrogen deficiency. The present study was undertaken to better understand how a low protein diet along with vitD insufficiency could affect bone metabolism using a rodent ovariectomized (OVX) model. Rats (n = 60) underwent ovariectomy (OVX) or sham operation. The first 15 days after surgery, all rats were fed a standard rodent diet. Thereafter, rats (n = 10/group) were fed a low protein diet (LP; 2.5 %) or a control diet (NP; 12.5 %) with 100 IU% vitD (+D; cholecalciferol) or without vitD (-D) for 45 days. The groups were as follows: SHAM + NP + D (control); SHAM + LP + D; SHAM + LP - D; OVX + NP + D; OVX + LP + D; OVX + LP - D. Body weight (BW) of control and OVX + NP + D groups increased while those feeding the LP diet, independently of vitD feedings, decreased (p %26lt; 0.05). The OVX + LP - D group presented the lowest serum Ca, phosphorus and osteocalcin levels and the highest CTX levels (p %26lt; 0.05). At the end of the study, total skeleton bone mineral content, proximal tibia bone mineral density, bone volume and trabecular number levels decreased as follows: SHAM + NP + D (controls) %26gt; SHAM + LP + D %26gt; OVX + NP + D %26gt; SHAM + LP - D %26gt; OVX + LP + D %26gt; OVX + LP - D (p %26lt; 0.05). A low protein diet negatively affected bone mass and magnified the detrimental effects of vitD and/or estrogen deficiencies.

• 出版日期2013-8