Hyperglycaemic emergencies are oft encountered DM complications in clinical practice. They are the most serious acute metabolic complications of diabetes mellitus and are associated with excess mortality. The incidence of DKA in the United States of America is 4.6 and 8.0 per 1000 person-years among patients with diabetes, whereas that of HHS is less than 1 per 1000 person-years[10
]. In sub-Saharan Africa data on incidence rates for the HEs are scarce. An earlier report by Ogbera et al[3
] showed that hyperglycaemic emergencies account for 40% of all DM related hospitalization with a preponderance of DKA admissions compared to that of HHS.
Hyperglycaemic emergencies occur in all age groups of people with DM and in this report we found that DKA and HHS admissions were recorded more in the 36–64 years age bracket while the least number of DKA and HHS hospitalizations were found in those below 35 years of age. This study documented the mean age of subjects with HEs to be 54 years and this is lower than those reported from some Western, Asian sub-Saharan African countries [11
]. In this report, the mean ages of subjects presenting with DKA and HHS [10
] were comparable and these findings are diametrically opposed to some other reports[11
] that showed a significant difference in the ages of people presenting with HHS and DKA. The noted difference between these reports and ours may be due to our inability to assess the C-peptide levels which would have helped in objectively classifying patients properly according to DM type. Of note in this report, is that gender was comparable in subjects presenting with HHS and those presenting in DKA.
Though precipitating factors for HEs are varied, infections, poor drug compliance and undiagnosed or new onset diabetes are factors that have consistently been reported as being associated with HEs [5
]. Although our findings are consistent with the aforestated scenario, it is pertinent to note that poor drug compliance was a major precipitant of HEs in our study subjects. Documented reasons for poor drug compliance in our patients ranged from poor accessibility to health facilities, high costs of drugs often resulting from polypharmacy because of co-morbidities and also ignorance on self care habits of DM. Reported rates of undiagnosed diabetes presenting as HEs range from 10.9%–50%[7
]. In this report undiagnosed DM accounted for 15% of the hyperglycaemic emergencies.
The low prevalence of hypertension of DM in our patients with type 2 DM may be explained by the fact the that some of the subjects were not previously known to have DM or hypertension and the presence of resultant hypotension from hyperglycaemic emergencies may mask the presence of hypertension. The mean age of our study population–may also partly explain the documented low prevalence of hypertension in this clinical scenario as ageing is associated with hypertension.
The duration of DM was associated with mortality outcomes as higher mortality rates were found in subjects with low duration of DM. Previously undetected cases of DM presenting in HEs may partly explain why this is so, since this group of patients fall under the low duration of DM category.
Electrolyte imbalances are the consequences of hyperglycemia, hyperosmolality, and acidosis. The biochemical parameters noted in this study were those of hypokalaemia. hyponatraemia, hypernatraemia and azotaemia and hyperkalaemia. These abnormalities occurred more in people with DKA except for hypernatraemia (HN) and hypokalaemia (HP) which occurred in higher percentages of subjects with HHS viz (12%,47% in HHS vs 2%,35% in DKA). Hypokalemia was the prevalent form of electrolyte imbalance observed in this Report. Hypokalaemia occurs as a a result of urinary losses in the face of a high osmotic gradient. Hyponatraemia, which was noted in about a third of subjects with types 1 and 2 DM often result from urinary losses and may be dilutional as water shifts extracellularly because of high serum osmolarity. Not surprising, serum hyperkalemia was seen only in a few patients and it's presence is explained by a shift of potassium from the intracellular to extracellular space because of acidosis from insulin deficiency and decreased renal tubular secretion. Azotemia which may be a resultant effect of volume contraction in patients with HEs was not objectively assessed as only urea levels of these patients were documented. However the presence of elevated urea levels was a prominent feature in our study subjects. Hypernatraemia, a rare feature of the HEs especially DKA may signify a response to reduction in circulating volume. The presence of hypotension, altered mentation and seizures in this report were infrequent occurring in 11 (10%), 26(23%) and 3(3%) of the subjects with HEs respectively. Seizures often occur in up to 25 percent of patients with hyperosmolar non ketotic state and may be generalized, focal, myoclonic jerking, or movement induced[16
]. In this report, seizures not surprisingly occurred only in subjects with HHS. Hyperglycaemic emeregencies often are associated with very high mortality in sub-Saharan Africa, both in the treated patients and those who are presenting to hospital with diabetes for the first time[6
]. The overall mortality rate of the HEs in this study was 20% and this figure is lower than those noted in some sub-Saharan African and Asian reports[7
]. Mortality rates of HEs from sub-Saharan Africa and Asia range from 30–44% [7
]. MacIssac et al [14
] reported overall mortality rates of HEs as low as 4.8%. The estimated mortality rate for DKA range between 5–10% and that for HHS varies from 10 to 50%[10
]. In this study, the case fatality of HHS at 35% was about twice that of DKA which was 18%. Our findings are in consonance with the general findings of higher case fatality rates of HHS compared with those of DKA [13
]. Some of the predictive factors for fatal outcomes of the HEs in this report were sepsis, diabetes foot ulceration, low duration of DM and being elderly. The results from this report with regards to classification into types 1 and 2 should be interpreted with caution since objective classification of DM into these two types requires the assessment of C-Peptide levels which was not done.
Limitations of the Study
1. We were unable to assess C peptide levels and this was as a result of financial constraints.