Glucose levels rise in the setting of relative insulin deficiency. The low levels of circulating insulin prevent lipolysis, ketogenesis, and ketoacidosis (62) but are unable to suppress hyperglycemia, glucosuria, and water losses. Levels of counter-regulatory hormones such as glucagon, catecholamines, cortisol, and growth hormone are elevated, increasing gluconeogenic substrates, gluconeogenesis, and glycogenolysis. Meanwhile, glucose utilization is decreased. Glucose levels rise, leading to glucosuria, osmotic diuresis, and dehydration (14). Those patients who are unable to maintain an adequate fluid intake to compensate for the urinary losses, for example, elderly patients, will develop marked hyperglycemia and a hyperosmolar state. Mental status changes are more common in HHS than in DKA because of the greater degrees of hyperosmolarity in HHS (63).
HHS typically presents with one or more precipitating factors, similar to DKA. Precipitating factors may include infection, cardiovascular events, trauma, drugs, or other illnesses (14). Acute infections include pneumonia, urinary tract infections, and sepsis, which account for approximately 32-50% of precipitating causes (13). Other less common precipitating factors include intestinal obstruction, acute pancreatitis, renal failure, hypothermia, severe burns, thyrotoxicosis, Cushing's syndrome, and acromegaly. Drug use and therapy may exacerbate hyperglycemia and stimulate ketoacid production. These include ^-adrenergic blocker, calcium-channel blockers, chlorpromazine, cimetidine, diazoxide, diuretics, ethacrynic acid, immuno-suppressive agents, l-asparaginase, loxapine, phenytoin, propranolol, and steroids (13).
HHS develops subacutely in time over days to weeks. Hyperglycemia increases glucosuria and water losses which further impair the ability to excrete excess serum glucose. Patients often complain of polyuria, polydipsia, lethargy, and weight loss. The classic presentation is altered sen-sorium, but patients also demonstrate signs of dehydration, weakness, tachycardia, and hypotension. A comparison of the varying abnormalities seen in DKA and HHS is listed in Table 2.
Diagnostic criteria delineating DKA and HHS.
Was this article helpful?