Quantifying Changes in Free-living Physical Activity of Rwandan Women Using Accelerometry Data after an Iron-biofortification Efficacy Trial.

Objectives: To quantify changes in free-living physical activity in Rwandan women before and after a 4.5 month feeding trial of biofortified beans. Methods: 145 Rwandan women (18-26 years) were randomized to receive either iron-biofortified beans or traditional beans for 5 months. Blood biomarkers and functional outcomes were measured before and after the feeding period. Free-living physical activity was assessed using the Actigraph GT3X accelerometer which the women wore for 5 consecutive days (3 weekdays and 2 weekend days). Total energy expenditure and metabolic equivalents were calculated. General linear models were used to evaluate the effect of the intervention on energy expenditure during free-living physical activity. Results: 58 women complied with the Actigraph wearing protocol. Women in both the treatment and control groups expended about 500 fewer calories after the intervention controlling for wear time. Change in ferritin in the intervention group but not the control group significantly predicted increased change in kilocalories expended. Conclusions: Changes in iron status from a biofortification trial significantly predict changes in daily energy expenditure.

Effects of an Iron-biofortification Feeding Trial on Physical Performance of Rwandan Women.

Objectives: To examine the effects of an iron-biofortified bean intervention on physical performance in Rwandan women assessed by VO2max and work efficiency. Methods: 145 Rwandan women (18-26 years) were randomized to receive either iron-biofortified beans or traditional beans twice daily for 5 months. Blood biomarkers and physical performance were measured before and after the feeding period. VO2max and work efficiency at 70 watts were assessed with a mechanically braked cycle ergometer (Monark 874E). Heart rate, O2, and CO2 were directly measured with the Cosmed K4B2 system. Non parametric tests and mixed effects models with repeated measures were used to evaluate the effect of the intervention on blood biomarkers and VO2max and work efficiency. Results: Serum ferritin significantly increased in the iron-biofortified group (4.0 μg/l increase in median in treatment group, 2.5 μg/l increase in median in control group; p=0.04). VO2max significantly increased in the iron-biofortified group compared to the control group (p=0.05). Work efficiency at 70 watts significantly increased over time but was not different between groups. Conclusions: Consumption of iron-biofortified beans significantly improved serum iron status and VO2max in Rwandan women but had no effect on work efficiency.

Clinical Chemistry Reference Intervals in a Rwandan Population.

Aim: To establish clinical chemistry reference intervals for the Rwandan population. Study Design: A population-based cross-sectional study. Place and Duration of Study: The study was carried out in three blood transfusion centres: Buhanda, Ruhango and Nyaruteja, between August and December 2011. Methods: Serum clinical chemistry tests were performed on a Cobas C311 automated chemistry analyzer. Results: Results of 187 subjects (age range: 17-54 years) presented as median, with 2.5th-97.5th percentiles (95% reference interval) in brackets are as follows: For males: alanine aminotransferase: 25 (12-43) U/L; aspartate aminotransferase: 29 (16-47) U/L; gamma-glutamyl transferase: 22 (9-77) U/L; total bilirubin: 0.6 (0.2-1.7) mg/dL; direct bilirubin: 0.2 (0.1-0.4) mg/dL; creatinine: 0.8 (0.5-1.1) mg/dL; uric acid: 5 (3-7) mg/dL. For males and females: alkaline phosphatase: 71 (27-122) U/L; amylase: 144 (50-235) U/L; lactate dehydrogenase: 176 (114-237) U/L; triglycerides: 82 (32-172) mg/dL; highdensity lipoprotein: 48 (29-86) mg/dL; glucose: 87 (70-114) mg/dL; total protein: 7.6 (6.5- 8.5) g/dL; albumin: 4.4 (3.4-5.4) g/dL; sodium: 142 (137-147) mmol/L; potassium: 4.1 (3.3-5.0) mmol/L; chloride: 106 (100-112) mmol/L; phosphate: 1.16 (0.87-1.49) mmol/L. Conclusion: The clinical chemistry reference values are in agreement with those reported in other African studies, with variations.

Thyroid Hormone Profile in Rwandan Students.

Aim: To illustrate the thyroid hormone profile in young adult students at moderate altitude in Rwanda. Study Design: A population-based cross-sectional study. Place and Duration of Study: The study was conducted among healthy university students living at Butare, Rwanda (altitude: 1,768 m, barometric pressure: 629 mm Hg) in December 2011. Methods: Venous blood was collected in the morning, after overnight fasting. TSH, total T3 and total T4 hormonal assays were performed in the laboratory of Butare University Teaching Hospital by classical sandwich ELISA technique for TSH and competitive ELISA technique for total T4 and total T3. Results: The results of 111 subjects (65 males and 46 females; mean age: 22 years, age range: 18-28 years) are as follows (mean ± SD): total T3: males: 0.9 ± 0.3 ng/mL, females: 1.3 ± 0.3 ng/mL; total T4: males: 6.4 ± 1.1 μg/dL, females: 9.3 ± 2.2 μg/dL; TSH: males: 1.8 ± 1.2 mIU/L, females: 1.9 ± 1.4 mIU/L. Conclusion: The results of our study compare well with findings of other studies, with a slight increase in serum TSH concentration as compared to sea level values. A comprehensive study needs to be done to establish reference intervals.

Haematological Values at Moderate Altitude in a Low-Income Population.

Aim: To illustrate haematological adaptation to moderate altitude in Rwanda. Study Design: A population-based cross-sectional study. Place and Duration of Study: The study was carried out at moderate altitude (1,649-1,768 m) among students of the National University of Rwanda and blood donors from Buhanda, Ruhango and Nyaruteja centres, from August to December 2011. Methods: Healthy volunteers (238 males and 106 females, age range: 18-40 years) were recruited in the study. Complete blood count was performed on a Coulter AcT 5diff and for some samples on a Sysmex KX-21N automated haematology analyzer. Results: Results (mean ± SD) were: erythrocyte count: males: 5.28 ± 0.53 X 1012/L, females: 4.72 ± 0.63 X 1012/L; haemoglobin concentration: males: 160 ± 16 g/L, females: 140 ± 18 g/L; haematocrit: males: 45 ± 4 %, females: 40 ± 5 %. The differential leukocyte count showed eosinophilia (4%) and increased lymphocytes (44%). Conclusion: The values for erythrocyte count, haemoglobin concentration, haematocrit, erythrocyte indices and leukocyte count are comparable to sea level values. The fact that haemoglobin concentration is not low as is the case in low-income populations living at sea level can be attributed to adaptation to moderate altitude.