The high burden of inpatient diabetes mellitus: the Melbourne Public Hospitals Diabetes Inpatient Audit.

OBJECTIVE: To determine the prevalence of diabetes in inpatients in Melbourne hospitals. DESIGN: Point prevalence survey of all inpatients in each hospital on a single day between 30 November 2010 and 22 November 2012. SETTING: 11 hospitals in metropolitan Melbourne including community, secondary and tertiary hospitals and one aged care and rehabilitation centre. PARTICIPANTS: 2308 adult inpatients in all wards apart from intensive care, emergency, obstetrics and psychiatry. MAIN OUTCOME MEASURES: Point prevalence of self-reported diabetes, details of current medication, self-reported frequency of complications. RESULTS: Diabetes status was obtained in 2273 of 2308 inpatients (98.5%). Of these, 562 (24.7%) had diabetes (95% CI, 22.9%-26.5%). Diabetes prevalence ranged from 15.7% to 35.1% in different hospitals (P < 0.001). Patients with diabetes were older, heavier and more likely to be taking lipid-lowering, antihypertensive and blood-thinning medications. Of 388 patients with complete medication information, 270 (69.6%) were taking oral hypoglycaemic agents alone or in combination with insulin, 158 (40.7%) were treated with insulin (67 [17.3%] with insulin alone) and 51 (13.1%) were not taking medication for diabetes. The frequency of diabetes complications was very high: 207/290 (71.4%) for any microvascular complication, 275/527 (52.2%) for any macrovascular complication and 227/276 (82.2%) for any complication. CONCLUSION: The high burden of diabetes in Melbourne hospital inpatients has major implications for patient health and health care expenditure. Optimising care of these high-risk patients has the potential to decrease inpatient morbidity and length of stay as well as preventing or delaying future complications. A formal Australian national audit of inpatient diabetes would determine its true prevalence and consequences, allowing rational planning to deal with shortcomings in its management.

Hypothesis: Musculin is a hormone secreted by skeletal muscle, the body's largest endocrine organ. Evidence for actions on the endocrine pancreas to restrain the beta-cell mass and to inhibit insulin secretion and on the hypothalamus to co-ordinate the neuroendocrine and appetite responses to exercise.

Recent studies indicate that skeletal muscle may act as an endocrine organ by secreting interleukin-6 (IL-6) into the systemic circulation. From an analysis of the actions of IL-6 and of additional literature, we postulate that skeletal muscle also secretes an unidentified hormone, which we have named Musculin (Latin: musculus = muscle), which acts on the pancreatic beta-cell to restrain the size of the (beta-cell mass and to tonically inhibit insulin secretion and biosynthesis. It is suggested that the amount of Musculin secreted is determined by, and is positively correlated with, the prevailing insulin sensitivity of skeletal muscle, thereby accounting for the hyperinsulinemia that occurs in insulin resistant disorders such as type 2 diabetes mellitus, obesity, and the polycystic ovary syndrome. In addition, it is postulated that Musculin acts on the hypothalamus (arcuate nucleus, dorsomedial hypothalamic nucleus) to co-ordinate the neuroendocrine and appetite responses to exercise. However, the possibilities that Musculin may act on additional central nervous system sites and that an additional hormone(s) may be responsible for these actions are not excluded. It is suggested that a search be made for Musculin, since analogues of such a substance may be of therapeutic benefit in the treatment of the current global diabetes and obesity epidemic.