Ventiliatory Function in Nigerians with Type 2 Diabetes

ABSTRACT

Reduced ventilatory function in type 2 diabetes has been reported in other parts of the world. This study aimed to assess the ventilatory function in Nigerians with type 2 diabetes and its relationship to the duration of symptoms of diabetes, glycaemic control, age, and body mass index (BMI). One hundred and one (101)patients with type 2 diabetes were matched to 104 control subjects with normal glucose tolerance. Historical and clinical data were documented and venous blood sampled for HbA1c in the diabetes group. Peak expiratory flow rate (PEFR), forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) and the ratio of the FEV1 to the FVC as a percentage (FEV1/FVC%) were measured for both groups. Study subjects and controls were similarly matched. Mean PEFR (L/s), FEV1 (L), and FVC (L) were 5.6±2.24, 2.36±0.74,and 2.94±0.90, respectively, in the diabetes group and 6.31±1.62, 2.58±0.62, and 3.19±0.79, respectively, in the control group (p=0.006, 0.02, and 0.03, respectively).The FEV1/FVC% was 81.90±24.17 in the diabetes group and 81.26±5.99 in controls (p= 0.86). Compared with predicted values for Nigerians, 11 (11%) of diabetes subjects had restrictive lung disease and 6 (6%) had obstructive lung disease while 1 (1%) of controls had restrictive lung disease and 5 (5%) had obstructive lung disease (c2=9.46, p=0.009). In multivariate analysis, age was inversely related to the PEFR (p=0.04). BMI was inversely related to PEFR, FEV1, and FVC (p= 0.01, 0.001, 0.002, respectively). Duration of diabetes was also inversely related to FEV1 (p= 0.02). HbA1c was not significant for any ventilatory index. It was concluded that Nigerians with type 2 diabetes have significantly lower ventilatory function (with a restrictive pattern),compared with matched controls. Symptom duration,age, and BMI are independent determinants of ventilatory function