The Association Between Nutritional Risk and Bone Stiffness in Elderly Men and Women in a Population-Based Study in Northeast Germany

Abstract

Background: The Geriatric Nutritional Risk Index (GNRI) has shown promising potential for identifying individuals at risk for osteoporosis in various patient cohorts. However, data from the general population confirming or refuting the usefulness of the GNRI as a risk factor for osteoporosis are sparse. We therefore aimed to clarify whether the GNRI is associated with the ultrasound-based bone stiffness index and the osteoporotic fracture risk in a sample of elderly men and women from the general population.

Methods: Data from 1417 participants in the Study of Health in Pomerania START-2 or TREND-0 aged 65 years or older with quantitative ultrasound measurements at the heel and GNRI values were examined. In cross-sectional linear and logistic regression models, associations between the GNRI and heel stiffness index or ultrasound-based osteoporotic fracture risk were examined. All analyses were repeated after stratification of the study population according to BMI (underweight/normal weight, overweight and obese).

Results: In underweight/normal weight individuals, higher, i.e., better, GNRI values had a positive effect on the stiffness index (β-coefficient per standard deviation increase in GNRI = 2.69, standard error = 1.00, p = 0.007). With increasing GNRI values, underweight/normal weight elderly men and women also had higher chances of a low osteoporotic fracture risk (odds ratio 1.42, 95% confidence interval 1.04-1.94, p = 0.026). Corresponding associations in overweight or obese individuals were absent.

Conclusions: In elderly men and women with underweight/normal weight, the GNRI is positively associated with the bone stiffness index and the related osteoporotic fracture risk. In this group, the GNRI may prove useful in identifying individuals with an elevated fracture risk.

Keywords: BMI; bone stiffness; elderly men and women; nutritional risk; osteoporosis; quantitative ultrasound; underweight.

Figure 1

Associations between the GNRI and the ultrasound-based stiffness index in underweight/normal weight (n = 240), overweight (n = 653) or obese (n = 524) study participants. Illustrated is the estimated stiffness index (solid line) with 95% confidence intervals (shaded area) for an average male study participant (aged 71 years, physically active, without diabetes mellitus or liver disease, with an eGFR of 71 mL/min/1.73 m²) with a BMI of 23, 28 or 33 kg/m². BMI, body mass index; eGFR, estimated glomerular filtration rate; GNRI, Geriatric Nutritional Risk Index; QUS, quantitative ultrasound.

Figure 2

Jitter plot illustrating the distribution of the GNRI according to the ultrasound-based osteoporotic fracture risk in 240 underweight/normal weight study participants. A t-test was used to compare group differences. GNRI, Geriatric Nutritional Risk Index; QUS, quantitative ultrasound.