Compared to 3 classifications of nutritional status – normal, obese and obese-malnourished – malnutrition in people with heart failure was found to have a significant negative effect on overall life expectancy, according to results from a new study in France.
Moreover, patients with chronic heart failure classified as both malnourished and obese had similar life expectancies to patients with the disease and normal nutritional status.
These findings were published in Nutrition Diary.
While malnutrition is a risk factor for adverse effects in people with heart failure, obesity often confers a protective effect, the authors noted. However, the effects of the interplay between obesity and malnutrition on heart failure patient mortality are not well understood, which prompted this retrospective study. All patients aged 18 and over with a primary diagnosis of heart failure between 2021 and 2016 from a French acute care hospital (public or private) were included in the analysis. International Classification of Diseases, Tenth Revision code 150 confirmed diagnosis of heart failure.
“Malnutrition is a risk factor for mortality, while obesity may play a protective role, a phenomenon called the ‘obesity paradox’,” explain the authors. “However, the effect of the obesity-malnutrition association on mortality has not been studied before.”
Overall, when comparing outcomes between patients with chronic heart failure and the normal, obese, and obese-malnourished state, malnutrition alone was linked to a 16% higher likelihood of life expectancy. reduced life (RR adjusted [aHR], 1.16; 95% CI, 1.14-1.18) at 1 year after heart failure diagnosis and 4% higher risk at 4 years (aHR, 1.04; 95% CI, 1.004-1.08 ).
In contrast, obesity was associated with a reduced risk of death of 25% at 1 year (aHR, 0.75; 95% CI, 0.73-0.78) and 15% at 4 years (aHR , 0.85; 95% CI, 0.81-0.90).
The observed mortality rates, meanwhile, were lowest at both ages 1 and 4 for the obese group and highest at these points for the malnourished group:
- 1 year: 13.6% (obese) vs 28.1% (malnutrition) vs 20.4% (normal nutritional status)
- 4 years: 29.3% vs. 41.4% vs. 35.0%, respectively
“In the group with only malnutrition, the more severe the malnutrition, the lower the probability of survival,” the authors pointed out. “In the obese-only group, all obesity classes had better survival than the non-obese groups.” For example, while severe obesity increased the risk of in-hospital death by 46% at 4 years (aHR, 1.46; 95% CI, 1.38-1.55), morbid obesity decreased this 35% risk (aHR, 0.65; 95% CI, 0.58-0.72).
Most patients in this analysis were classified as severely or moderately malnourished and standard (body mass index [BMI], 30-40 kg/m2) or morbid (BMI, 40-50 kg/m2) obesity. Malnutrition criteria also varied for patients, with patients under 70 and 70 and over having to meet at least 1 of the different criteria:
- Under 70: weight loss of at least 10% vs a previous value (or 5% in 1 month), BMI less than or equal to 17 kg/m2, albumin less than 30 g/L or prealbumin less than 110 mg/L (if no inflammatory syndrome)
- 70 years and over: weight loss of at least 5% in 1 month or at least 10% in 6 months, BMI less than 21 kg/m2, or albumin level below 35 g/L
Because the authors’ results contradict some of the published literature, particularly the US studies they highlight – which they attribute to differences in diet and physical activity between the 2 countries – future studies should explore the paradox of obesity, particularly with regard to morbid obesity. .
However, this does not detract from the importance of their findings, as they also reiterate the findings of previous studies on the protective role of obesity and the body’s adverse reaction to malnutrition in people with obesity. heart failure. The main strengths of these results lie in the use of a national database for data sampling and the long follow-up times, and the main limitations include the measurement of hospital mortality and the use of a only database (the French database on hospital discharges, or Program de Médicalisation des Systèmes d’Informations) for nutritional status.
“Further studies are needed to explore the possible protective effect of increased body fat during heart failure, and further interventional studies should be conducted to confirm our findings,” the authors concluded. “It would also be interesting to explore in more detail the pathophysiological mechanisms that could explain this effect.”
Carime NA, Cottenet J, Clerfond G, et al. Impact of nutritional status on heart failure mortality: a retrospective cohort study. Nutr J. Published online January 6, 2022. doi:10.1186/s12937-021-00753-x