Association Between Nutritional State and Phase Angle in Symptomatic and Asymptomatic HTLV-1 Infected Patients

Abstract

IntroductionThe nutritional status of symptomatic and asymptomatic human T-cell lymphotropic virus type 1 (HTLV-1) infected patients is understudied. The phase angle (PA) has been described in the scientific literature as a prognostic indicator of nutritional status, but this has not been sufficiently discussed in the literature. Therefore, neither the impact of the infection nor the disease’s progression is sufficiently known regarding the nutritional status, body condition or composition.ObjectiveTo compare the nutritional status of symptomatic and asymptomatic adult individuals infected by HTLV-1, using the PA and anthropometric measures as a prognostic indicator in the HTLV-1 infected population.MethodologyThis was an observational, cross-sectional study with symptomatic and asymptomatic HTLV-1 patients followed up at the Neurology outpatient clinic of the Evandro Chagas National Institute of Infectious Diseases (INI-FIOCRUZ), Brazil, from September 2015 to September 2019. Anthropometric measures and indices (body weight, height, body mass index-BMI, mid-upper arm circumference-MUAC, triceps skinfold - TSF, and mid- arm muscle circumference-MUAC), and bioimpedance (phase angle-PA, percentage of lean mass-%LM, and percentage of fat mass-%FM) were checked to assess the nutritional status. Anthropometric variables were classified according to reference values and compared between groups (symptomatic and asymptomatic). Individuals were considered malnourished when at least one of the nutritional assessment results was outside the reference values. PA was correlated with the nutritional status, and groups of symptomatic and asymptomatic were compared to each other. The R-project® program version 3.0.2 was used to analyze the data. Differences were considered significant when the p-value was ≤ 0.05.ResultsNinety-one patients were evaluated, 33 (36.3%) asymptomatic and 58 (63.7%) symptomatic. The majority were female (61.5%) and the median age was 60 (55-58) years. Symptomatic participants, compared to asymptomatic, had a lower proportion of overweight/obesity (51.7% vs 78.8%; p =0.0171), lower BMI (25.47 ± 5.06 kg/m2 vs 30.08 ± 5.61 kg/m2; p = <0.001), MUAC (29.56 ± 5.13 cm vs 33.22 ± 4.21 cm; p =0.0011), and %FM (30.75% vs 36.60%; p =0.0064), however, had a higher %LM (68.95% vs 63.40%; p =0.0299). All participants presented PA, however there was no difference between symptomatic (5.74º ± 1.18) and asymptomatic (6.21º ± 1.16).ConclusionOverweight and obesity were prevalent, especially among asymptomatic participants. Symptomatic participants had lower BMI, MUAC and %FM. Mid-upper arm circumference was considered a good parameter for monitoring the nutritional status of people with HTLV, mainly in situations where weight measurement is not viable. PA was altered in both groups, therefore, it cannot be used as a disease progression indicator, but it does indicate that HTLV infection alone should be a risk of cellular membrane integrity damage. Studies using PA assessment in HTLV-1 carriers are needed.AUTHOR’S SUMMARYHTLV is a disease very little explored, and in the scientific field of nutrition it is no different, we found few studies that associate this population and their nutritional status. In academic literature we can find the association of weight, height and BMI, rare studies with bioimpedance assessments.Until this moment, no study has associated nutritional status with the phase angle, which is being used in several infectious diseases as a prognostic indicator of cell membrane integrity.In this study, we note that even though the phase angle values are not significant, they show that, regardless of the symptoms, patients who are infected with the HTLV virus are already considered to have damage to the membrane integrity, which makes us emphasize the importance of new studies to a better understanding of factors related to weight gain and probable nutritional deficiencies.