Is There a Difference in Lean and Fat Mass in HF Patients Based on NYHA Classifications (I-II versus IIII-V)?

Introduction: As NYHA Class increases from I (ordinary physical activity does not cause undue fatigue), to Class IV (Symptoms are present while at rest) physical limitations become severe. It has previously been shown that HF patients have increased fat within the muscle thus decreasing exercise performance and tolerance. It is unclear if all NYHA classes are similarly affected. Hypothesis: HF patients with NYHA class III-IV will have more fat and less lean mass than those with NYHA class I-II. Methods: Secondary data analysis using cross sectional data from N=253. The parent study was a multicenter study about nutrition and body composition among patients with HF (preserved or reduced, and NYHA classification I-IV) who had been on a stable medication regimen, able to participate in dual-energy X-ray absorptiometry scan and/or BodPod body composition measures, able to read and speak English, and had no cognitive impairment. Women and men were analyzed separately due to known differences in fat and lean mass. Results: Table 1: Sample characteristic’s Testing the hypothesis using 2-way ANOVA and comparing the percentage of body weight that is lean and fat mass in NYHA class I-II vs III-IV found the interaction of gender and NYHA was not significant in either % lean or %fat (p=0.221, 0.190 respectively). NYHA class by itself was not significant (p=0.067) in %lean but was significant in %fat (p=0.046). Gender was significant in both %lean and %fat with men having 9.6% less fat (1.139 SE) and 9.8% more lean mass (1.066 SE) (p≤0.001). NYHA class III-IV had 2.3% (1.139 SE) more fat than those in NYHA class I-II. The R squared was 0.265 and adjusted R squared was 0.256. Conclusions: Part of our hypothesis was correct in that NYHA class III-IV had more fat mass than those in class I-II, but no difference was found in lean. This is an unexpected finding as healthy people gain fat mass while losing lean mass as they age. Additional studies are needed to further examine this result.