Materials and methods: This was a descriptive cross-sectional study conducted in Iganga municipality, located along the Kampala- Malaba highway about 150 km away from the capital city of Uganda. The study was approved by the Institutional Review Committee of Clarke International University.
Sample size calculation
According to previous study carried out in a similar location in 2013 [13] the prevalence of pre-diabetes was estimated at 8.6%. Using the formula for sample size calculation for proportion
n= Z2P (1 - P) /d2
Where: n=The desired sample size.
Z= Critical values of normal distribution at 95%, which corresponds to 1.96
P= The proportion of the target population estimated to have pre-diabetes.
d=Estimated margin of error 5%
n=1.962 0.86 (1-0.86)/(0.05)2
n=121
Adjusting for the sample collection errors and loss of samples, the sample size was adjusted by 5% to approximately 127 and rounded off to 130. The minimum sample size required for the study was 130.A list of all the households was obtained from the district health and the local council V offices. Sampling of the villages was based on probability proportionate to population. 130 males and females aged 13 to 60 years were randomly sampled from a sampled household for the survey. Each day, after selecting the centre of the village, a bottle was tossed and a direction to the first household depended on the direction the bottle top faced. After sampling the first participant from the first household, the researchers took right direction from that house to the next household. The procedure was followed until the required sample size was met.
After obtaining a written informed consent, an appointment was given to the eligible participant and a clear instruction for fasting was provided. The following morning, measurements of height, weight and blood pressure (BP) were carried out. 4ml of blood was collected from each participants in fluoride/oxalate bottles for fasting blood glucose and a structured questionnaires administered by a trained interviewer to collect information on risk factors for pre-diabetes. All the participants with fasting blood glucose above 6.1 mmol/L but below 6.9 mmol/L were given appointment for Oral Glucose Tolerance Test (OGTT). The procedure for the OGTT was as described previously (27). Briefly, after an overnight fasting, blood sample was drawn from the participant and then 75g of pure glucose was dissolved in 250ml of pure drinking water, flavored with lemon juice. Participants took the preparation within 5 minutes after which blood samples were obtained at 30, 60, 90, and 120 min for the measurement of glucose. Body mass index (BMI) was then calculated as weight in kilograms divided by the square of height in meters. Participants were then classified as underweight if BMI was <18.5 kg/m2, normal weight 18.5-24.9kg/m2 and overweight if BMI was 24.9 -30kg/m2 and obese if BMI was >30kg/m2. Two blood pressure (BP) measurements were taken 5 to 30 minutes apart with participant seated; using a calibrated BP TRANSTEK machine. The mean of the two measurements was then calculated. The BP of the participant was classified as hypertensive if their Systolic BP >140mmHg diastolic BP >90mmHg. IFG and IGT were defined based on WHO criteria (11). Data were double entered in Epi Data, cleaned and exported to STATA 10 (StataCorp, College Station, TX, USA) for analysis. The prevalence of pre-diabetes was calculated as the proportion of those participants classified as pre-diabetic against the total numbers of the participants. To determine the risk factors for pre-diabetes, we used prevalence rate ratios using modified poisson regression analysis model. 95% confidence level was used in the analysis and statistical significance was set at p < 0.05.