Macronutrient intake and body composition changes during anti-tuberculosis therapy in adults

Abstract

Background: Malnutrition is common in patients with active tuberculosis (TB), yet little information is available on serial dietary intake or body composition in TB disease.

Objective: To evaluate macronutrient intake and body composition in individuals with newly diagnosed TB over time.

Design: Adults with active pulmonary TB (n = 191; 23 with multidrug resistant TB (MDR-TB) and 36 culture-negative household contacts (controls) enrolled in a clinical trial of high-dose cholecalciferol (vitamin D3) were studied. Macronutrient intake was determined at baseline, 8 and 16 weeks. Serial body composition was assessed by body mass index (BMI; kg/m(2)) and bioelectrical impedance analysis (BIA) to estimate fat mass and fat-free mass. Descriptive statistics, repeated measures ANOVA for changes over time and linear regression were used.

Results: At baseline, mean daily energy, protein, fat and carbohydrate (CHO) intakes were significantly higher, and body weight, BMI, fat-free mass and fat mass were significantly lower, between TB subjects and controls. These remained significant after adjusting for age, gender, employment status and smoking. In all TB subjects, baseline mean daily intakes of energy, fat and protein were adequate when compared to the US Dietary Reference Intakes and protein significantly increased over time (p < 0.0001). Body weight, BMI, and fat and fat-free mass increased over time. MDR-TB patients exhibited lower body weight and fat-free mass over time, despite similar daily intake of kcal, protein, and fat.

Conclusions: Macronutrient intake was higher in TB patients than controls, but TB-induced wasting was evident. As macronutrient intake of TB subjects increased over time, there was a parallel increase in BMI, while body composition proportions were maintained. However, individuals with MDR-TB demonstrated concomitantly decreased body weight and fat-free mass over time versus drug-sensitive TB patients, despite increased macronutrient intake. Thus, MDR-TB appears to blunt anabolism to macronutrient intake, likely reflecting the catabolic effects of TB.

Keywords: Body composition; Diet; Macronutrient; Tuberculosis.