Hyperkalemia - frequency in a group of hypertensive diabetics

ABSTRACT

To evaluate the frequency of hyperkalemia in a cohort of hypertensive diabetic patients. A prospective analytical cohort study. The study was carried out in department of medicine [nephrology] Military Hospital [MH] and Armed Forces Institute of Urology [AFIU] Rawalpindi from Jun 2007 - Jun 2009. A total of 110 hypertensive, middle aged diabetic patients attending medical OPD in MH and AFIU. Rawalpindi were followed over two years from Jun 2007 - Jun 2009 for development of hyperkalemia and monitored for changes in eGFR, Serum Urea, creatinine and blood glucose random besides changes in blood pressure and ECG findings. SPSS version 13 was employed for statistical analysis. During the course of study 9 patients were lost to follow up. There were 7 deaths among study subjects before the end of study after about ten to twelve months. Out of the 94 patients followed up mean Serum Urea at the end of study was 13.50 mmol/l against a serum creatinine level of 2.26mmol/l and an estimated GFR of 21.08 ml/ min. The frequency of raised serum Potassium of 5.1-6.0 mmol/l was 46.08% and 26.59% of the patients had serum Potassium of 6.1-7.2 mmol/l at the end of study. This was against an initial level of 4.5-5.0 mmol/l in 100% of the study subjects. Paired sample t-test revealed significant changes in each variable studied but a borderline positive correlation of 0.619 was observed only between serum potassium and change in eGFR at the end of study. The mean blood glucose random dropped from 16.14 mmol/l to 10.41 mmol/l. at the end of study mean systolic BP was 122mm Hg and diastolic BP 80.2mm Hg. The ECG revealed tall T waves in 64.9% of cases while at the start of study all subjects had their electrocardiograms within normal limits. There was a trend of increase in frequency of tall T waves with the rise of serum potassium levels. Raised serum potassium is a significant potential complication among long standing diabetics with covert nephropathy treated with ACE inhibotrs, ARBs, potassium sparing diuretics or a combination of these drugs. Co morbidities and development of this complication must therefore be considered by physicians when dealing with such patients