Nutritional Status in a Contemporary Urban Population-Based Cohort: Prevalence, Clinical Associations and Long-Term Health Outcomes

Background: Nutritional deficiencies are associated with poor prognosis in a wide range of illnesses. However, the prognostic impact of poor nutritional status with respect to long-term all-cause mortality in the general non-diseased population is not well described. Objectives: This study sought to report the prevalence, clinical associations, and prognostic consequences of poor nutritional status in a contemporary urban population in Germany. Methods: A cohort of 8398 participants from the LIFE-Adult Study was enrolled. Four objective nutritional scores, the Prognostic Nutritional Index (PNI), the Controlling Nutritional Status Score (CONUT), the Nutritional Risk Index (NRI), and the Triglyceride Cholesterol Body Weight Index (TCBI), were calculated at baseline, and participants’ nutritional status was classified according to score tertiles. The relationship between nutritional status and common risk factors as well as major diseases was assessed. In addition, the association between poor nutritional status at baseline and the risk of all-cause mortality during a seven-year follow-up period was examined. Results: According to the WHO definition of obesity, the LIFE-Adult Study cohort was, on average, overweight, with almost two-thirds of participants (67%) having a BMI ≥ 25 and only 1% being underweight. However, poor nutritional status was not associated with a specific BMI category. Higher age, female sex, cancer, and chronic kidney disease were more common, whereas active smoking and hypercholesterolemia were less prevalent among participants in the lowest PNI tertile (p < 0.01). In the overall population, the cumulative incidence of all-cause mortality was significantly higher among participants in the lowest PNI, NRI, and TCBI tertiles and the highest CONUT category (log-rank test, p < 0.01 for PNI, CONUT, and NRI, and p < 0.04 for TCBI, respectively). After adjustment for confounding factors, the lowest PNI and NRI tertiles and the highest and medium CONUT categories remained independently and significantly associated with an increased risk of all-cause mortality (all p < 0.01) in multivariable Cox regression analyses. TCBI was not associated with all-cause mortality in any regression model. Conclusions: Poor nutritional status is associated with increased mortality in the general population. Clinical trials are needed to prospectively evaluate the efficacy of nutritional interventions on health outcomes.