Protein intake, malnutrition, and its association with bone health after a hip fracture: A 3-month prospective study.

Abstract

In this study, we describe the change in protein intake, nutritional status, bone markers, and bone mineral density (BMD) in older patients recovering from a hip fracture, from post-surgery till 3 months. Additionally, we explore the association between protein intake with bone markers, quantitative ultrasound (QUS) and BMD, and nutritional status with QUS and BMD. A 3-month prospective study in 96 adults aged ≥70 years with an acute hip fracture was conducted. Assessments after surgery and 3 months included protein intake (questionnaire), nutritional status [Mini Nutritional Assessment Short Form (MNA-SF)], procollagen type I N-terminal propeptide (PINP), C-terminal telopeptide of type I collagen (CTX), insulin-like growth factor 1 (IGF-1), parathyroid hormone (PTH) levels, QUS parameters, and BMD (dual-energy X-ray absorptiometry). Associations were assessed by adjusted linear mixed models. At baseline, half of the patients (mean age 84 years, 63% females) had a low protein intake (<0.8 g/kg/d), which did not change over time. The patients had significant weight loss (median 3.6 kg) and the prevalence of (being at risk of) malnutrition increased from 20% to 64%. The PINP and IGF-1 levels increased over time, the CTX level remained stable, and the PTH level decreased. The protein intake was only associated with a QUS parameter in females (estimate 0.123, 95% CI 0.022-0.223). A higher pre-fracture MNA-SF status was associated with higher BMD in the total body (estimate 0.048, 95% CI 0.015-0.080), spine (estimate 0.085, 95% CI 0.025-0.144), total hip (estimate 0.055, 95% CI 0.018-0.093), and trochanter (estimate 0.057, 95% CI 0.018-0.096). IGF-1 was associated with PINP (estimate 1.215, 95% CI 0.363-2.066). A good nutritional status is associated with higher BMD in older hip fracture patients. The role of protein for bone health in these patients remains unclear. After a hip fracture, there is an increase in PINP.