Ventilatory capacity indices in Malawian children

Area of Science:

• Pulmonary physiology
• Pediatric respiratory health
• Anthropometry

Background:

• Establishing normative data for ventilatory capacity is crucial for diagnosing respiratory conditions.
• Existing reference values for lung function may not accurately represent diverse ethnic populations.
• Understanding ethnic and regional variations in ventilatory capacity is essential for accurate health assessments.

Purpose of the Study:

• To compare ventilatory capacity indices in healthy Malawian school children with those of other ethnic groups, including Caucasians.
• To establish appropriate reference values for interpreting lung function tests in Malawian children.
• To investigate the correlation between ventilatory capacity, age, sex, and body size in Malawian children.

Main Methods:

• Study conducted in two urban primary schools in Blantyre, Malawi.
• Involved 514 healthy school children (230 boys, 284 girls) aged 6–17 years.
• Measured forced vital capacity (FVC), forced expiratory volume in one second (FEV1), peak expiratory flow rate (PEFR), FEV1/FVC ratio (FEV%), weight, and height.

Main Results:

• Ventilatory capacity indices (FEV1, FVC, PEFR) strongly correlated with body size and age in both sexes.
• Mean FEV1 and FVC were higher in boys than girls (9.8% and 10.8%, respectively); PEFR difference was non-significant.
• Malawian children showed significantly lower FEV1 and FVC compared to European children (20.5–23% difference), and a 12% difference in PEFR, but were similar to other African and Caribbean children.

Conclusions:

• Prediction equations derived from this study are recommended for interpreting ventilatory capacity in Malawian children, rather than Caucasian reference values or ethnic scaling factors.
• Further research is needed to compute regional reference values, considering factors like physical activity, environment, altitude, nutrition, and smoking.
• Accurate interpretation of lung function in Malawian children requires region-specific normative data.