Among 384 DM patients, 61.5% of the respondents were males and 38.5% were females, 50.3% were type one and 49.7% were type two DM. The current study showed that the overall prevalence of anemia in DM patients was 19%. This prevalence is in agreement with the studies done in other countries [9–11]. This over representation of males might be due to: the prevalence of DM is higher in males than females in the study area, mostly females prefer to go to Traditional healers to use traditional medicine than using hospitals and other health facilities and Most females were excluded due to iron therapy for anemia correction.
This study revealed that anemia is significant in Type two DM with AOR of 4.17 (95% CI = 2.58, 8.56) and anemia is also associated with duration of Diabetes Mellitus for greater than eleven years are seven times (AOR 7.47, 95% CI 1.51, 37.07) more likely to develop anemia than patients with DM for less than five years. This result is in agreement with other studies [12, 13].
This study also showed that the prevalence of anaemia increases with older ages (27.4%) of DM patients whose age is greater than 60 years are anemic. This result is in agreement with a study in Israel, which indicates age has a significant association with anaemia in DM patients . Although it was previously believed that declines in hemoglobin levels might be a normal consequence of aging, evidence has accumulated that anemia does reflect poor health and increased vulnerability to adverse outcomes in older persons.
The result of this study shows that 13.8% of the population with diabetes have clinically significant chronic kidney disease (CKD), as defined by an eGFR <60 and 60–89 ml/min/1.73 m2, respectively. This finding is in agreement with a study in USA which says 15.9% of participants had at least moderately reduced kidney function .
The prevalence of albuminuria in this study is 33.1%, of these 14.1% had moderate renal failure and 10.7% had mild renal failure. Sixty five percent of DM patients who have a normal albumin level in their urine had a normal renal function. This result is in agreement with a study in Israel which shows prevalence of elevated albuminuria (micro or macroalbuminuria) was 38.1%. 8.1% of patients had moderate and 31.4% had mild renal impairment .
The study results showed that there is a significant association between anaemia and renal function. Diabetes mellitus patients with a mild renal failure have 4 times greater (AOR = 4.29, 95% CI = 1.14, 16.13) risk to be anemic than DM patients with a normal renal function. As the glomerular filtration rate increase, the risk to be anemic will decrease dramatically. Diabetes mellitus patients with a moderate renal failure have 11 times greater (AOR = 11.13, 95% CI = 2.69, 45.94) risk to be anemic than a normal renal function. This finding is in agreement with a study in UK, which indicates from anemic patients 36% with moderate renal failure and 9% of those with mild renal failure .
In this study, the relation between HGB and eGFR became negatively linear, as the estimated glomerular filtration rate decreases, the level of haemoglobin increases. The result of this study is in line with a retrospective study in UK, the prevalence of anemia increased progressively with worsening CKD. People with CKD stage 3 accounted for the largest number of people with anemia; 18% (95% CI13–24) had HGB < 110 g/l. Most patients with diabetes and anaemia can be identified by examining patients with moderate to severe renal impairment. These strong links between the kidney failure and anaemia in diabetes probably reflect the unique vulnerability of the renal microcirculation to damage in diabetes .
Renal function as measured by eGFR was the strongest predictor of anemia. Additional factors present in diabetes mellitus patients may contribute to the development of increased risk for anemia in patients with diabetes. These factors are: Age of patients, Type of DM, and duration with DM. The strengthen of this study is that it is one of few studies in developing countries where chronic disease like DM becoming more common but the study is not without limitations and the limitations of this study are lacks control groups, one time GFR is measured only one time which may not tell us the details of renal problem, as well proteinuria is measured only once this may be affected by different factors at that spot rather than being pathological condition and small sample size used for the study and which is not able to generalize to the whole population of Ethiopia and inclusion of young age of Participants may also affect the result.