The nutritional status of patients with tuberculosis in comparison with tuberculosis-free contacts in Delft, Western Cape

Abstract

Objective: To report on the nutritional status of newly diagnosed patients with pulmonary tuberculosis in comparison to contacts who are tuberculosis free. Design: This was a community-based case-control study. Setting and subjects: The study was conducted in Delft, a periurban community in the Western Cape. Forty-three newly diagnosed patients with tuberculosis were recruited as cases and matched according to age, gender and race to 43 tuberculosis-free contacts. Outcome measures: Each participant was interviewed and completed a structured questionnaire to provide demographic information. Weight was measured to the nearest 0.1 kg and height to the nearest 1 mm. Mid-upper-arm circumference (MUAC) was measured to the nearest 1 mm and skinfold thickness measurements to the nearest 0.2 mm. The 24-hour dietary recall method was used to obtain dietary information and analysed in the nutrition database of the Medical Research Council in order to translate foods into nutrients. Biochemical analyses were carried out to measure concentrations of transferrin, albumin, C-reactive protein (CRP), ferritin, zinc, copper and vitamins A and E. Means (± standard deviation) and confidence intervals were used to describe serum micronutrient and biochemical levels. Medians (minimum and maximum) were used to describe the nutrient intake and anthropometric status of patients. Results: The median body mass index for tuberculosis cases was 18.80 kg/m² [interquartile range (IQR) 14.35, 32.11] and for tuberculosisfree contacts 21.17 kg/m² (IQR 16.75, 34.98), with a significant difference between the groups with a p-value = 0.001. There was a statistically significant difference in weight (p-value = 0.002) and MUAC (p-value = 0.000) between groups; and in ferritin (p-value = 0.000) and CRP (p-value = 0.000) in patients with tuberculosis; while albumin (p-value = 0.000), serum zinc (p-value = 0.000) and serum vitamin A (p-value = 0.000) were significantly lower in cases. Conclusion: Newly diagnosed patients with tuberculosis have a poorer nutritional status than their tuberculosis-free counterparts. This may be a result of the acute phase response, increased metabolism and anorexia.