Profound spontaneous hypoglycaemia in congestive heart failure

Development and validation of a prediction model for insulin-associated hypoglycemia in non-critically ill hospitalized adults

OBJECTIVE

To develop and validate a multivariable prediction model for insulin-associated hypoglycemia in non-critically ill hospitalized adults.

RESEARCH DESIGN AND METHODS

We collected pharmacologic, demographic, laboratory, and diagnostic data from 128 657 inpatient days in which at least 1 unit of subcutaneous insulin was administered in the absence of intravenous insulin, total parenteral nutrition, or insulin pump use (index days). These data were used to develop multivariable prediction models for biochemical and clinically significant hypoglycemia (blood glucose (BG) of ≤70 mg/dL and <54 mg/dL, respectively) occurring within 24 hours of the index day. Split-sample internal validation was performed, with 70% and 30% of index days used for model development and validation, respectively.

RESULTS

Using predictors of age, weight, admitting service, insulin doses, mean BG, nadir BG, BG coefficient of variation (CVBG), diet status, type 1 diabetes, type 2 diabetes, acute kidney injury, chronic kidney disease (CKD), liver disease, and digestive disease, our model achieved a c-statistic of 0.77 (95% CI 0.75 to 0.78), positive likelihood ratio (+LR) of 3.5 (95% CI 3.4 to 3.6) and negative likelihood ratio (-LR) of 0.32 (95% CI 0.30 to 0.35) for prediction of biochemical hypoglycemia. Using predictors of sex, weight, insulin doses, mean BG, nadir BG, CVBG, diet status, type 1 diabetes, type 2 diabetes, CKD stage, and steroid use, our model achieved a c-statistic of 0.80 (95% CI 0.78 to 0.82), +LR of 3.8 (95% CI 3.7 to 4.0) and -LR of 0.2 (95% CI 0.2 to 0.3) for prediction of clinically significant hypoglycemia.

CONCLUSIONS

Hospitalized patients at risk of insulin-associated hypoglycemia can be identified using validated prediction models, which may support the development of real-time preventive interventions.

Spontaneous hypoglycemia associated with congestive heart failure attributable to hyperinsulinism

OBJECTIVE

To report a case of spontaneous hypoglycemia associated with congestive heart failure in an adult.

METHODS

We describe a 72-year-old man in whom profound hypoglycemia (serum glucose level, 21 mg/dL) developed during an exacerbation of heart failure. Clinical and laboratory data are reviewed.

RESULTS

An inverse relationship was found between both serum insulin and C peptide levels and serum glucose level. Serum glipizide and glyburide levels were undetectable, and no insulinoma was found on radiologic imaging. Hypoglycemia resolved after alleviation of the congestive heart failure.

CONCLUSION

In this case, the hypoglycemia was attributed to hyperinsulinemia. Possible mechanisms include impaired insulin degradation and shunting of portal blood into the systemic circulation.

Lower arterial glucose concentrations in lambs with aortopulmonary shunts after an 18-hour fast

Spontaneously occurring hypoglycemia has been described in children with severe acute congestive heart failure. Hypoglycemia may be the result of an increase in glucose utilization in tissues, a decrease in glucose production, or a decrease in the dietary intake of nutrients. To determine whether hypoglycemia may also occur in congenital heart disease with volume overloading, we investigated glucose metabolism during and after an 18-hour fast in nine lambs with an aortopulmonary left-to-right shunt and nine control lambs. Plasma levels of hormones involved in the endocrine control of glucose metabolism were determined. The glucose production rate (rate of appearance [Ra]) was studied using [U-13C]glucose. Gluconeogenesis through the Cori cycle was estimated by measuring glucose 13C recycling. The arterial glucose concentration (3,409 +/- 104 v 4,338 +/- 172 micromol/L, P < .001) and Ra of glucose (16.97 +/- 0.89 v 25.49 +/- 4.28 micromol x min(-1) x kg(-1), P < .05) were lower in shunt versus control lambs. There were no differences in hormone levels between control and shunt lambs. Fractional glucose 13C recycling via the Cori cycle (6.9% +/- 2.8% v 7.1% +/- 2.5%) and gluconeogenesis from pyruvate and lactate (1.24 +/- 0.58 v 1.95 +/- 0.67 micromol x min(-1) x kg(-1)) were similar in both groups of lambs. The sum of glycogenolysis and gluconeogenesis from precursors other than pyruvate and lactate was lower in shunt versus control lambs (15.73 +/- 1.07 v 23.54 +/- 4.27 micromol x min(-1) x kg(-1), P < .05). In conclusion, after an 18-hour fast, the arterial glucose concentration is lower in lambs with aortopulmonary shunts. This lower glucose concentration is associated with a decreased glucose production rate. In shunt lambs, glycogenolysis is decreased, while there is no difference in gluconeogenesis or hormonal control.

Hypoglycemia in hospitalized nondiabetic older patients

OBJECTIVES

To analyze the clinical characteristics, associated risk factors, and outcome of hypoglycemia in nondiabetic hospitalized older patients.

DESIGN

A retrospective case control study.

PARTICIPANTS

Sixty patients, aged 65 years and older, in the acute medical and geriatric wards who developed hypoglycemia. A control group was composed of 83 older patients, sex and age matched, in orthopedic and surgery wards who were undergoing corrective surgery for hip fracture or hernioplasty.

MEASUREMENTS

For all patients, data for the following variables were abstracted from the charts: age, sex, degree of hypoglycemia, clinical presentation of hypoglycemia, number and duration of hypoglycemia episodes, nutritional state, and blood chemistry analysis. Risk factors were defined as nutritional state, heart failure, renal or liver disease, malignancy, and infection or sepsis.

RESULTS

Mean blood glucose in hypoglycemic cases was 38.9 +/- 7 mg/dL. Symptoms and signs of hypoglycemia were noted in only 38.4% (23/60) of patients. All identified risk factors except cachexia were found significantly more frequently in the hypoglycemic patients than in the control group. Mean total number of risk factors was greater in the hypoglycemic group than in the control group, 2.97 +/- 1.1 versus 1.64 +/- .8, respectively (P < .001). In a multivariant logistic model, low plasma albumin level, liver disease, malignancy, and congestive heart failure were significant predictors of hypoglycemia. In-hospital mortality rate was higher among the hypoglycemic patients, 48% versus 18.1% (P < .001), and was independent of the degree of hypoglycemia or the number of hypoglycemic episodes. Mortality was correlated significantly with the number of risk factors (3.4 +/- 1.1 vs 2.5 +/- 1.1; P = .006). Hypoglycemia remained a significant predictor of mortality (OR = 3.67; 95% CI, 1.2-11.2) even after the adjustment for other risk factors.

CONCLUSIONS

Hypoglycemic episodes occur even among nondiabetic hospitalized older patients. Symptoms and signs of hypoglycemia were noted in only two-fifths of the patients. Albumin less than 3.0 g%, liver disease, renal insufficiency, malignancy, congestive heart failure, and sepsis were statistically significant predictors of developing hypoglycemia. The overall mortality rate was significantly higher among the hypoglycemic patients and was independent of hypoglycemia levels. Mean total number of risk factors was significantly higher among those who died compared with hypoglycemic patients who survived. Based on the present study, the estimated odds of mortality in an older patient with hypoglycemia were 3.67 times higher than in those without hypoglycemia.

Glucagon: prehospital therapy for hypoglycemia

STUDY OBJECTIVE

This study evaluated the efficacy of glucagon for prehospital therapy of hypoglycemia in patients without IV access.

DESIGN

Prospective clinical trial.

SETTING

Prehospital in a busy, urban emergency medical services system.

TYPE OF PARTICIPANTS

Fifty consecutive patients presenting with documented hypoglycemia (ChemStrip BG less than or equal to 80 mg/dL) and symptoms of decreased level of consciousness, syncope, or seizure were enrolled.

MEASURES AND MAIN RESULTS

Data collected included pretreatment (ChemStrip BG) and post-treatment serum glucose (hospital assay) as well as assessment of level of consciousness by a quantitative measure, the Glasgow Coma Score, and by a qualitative scale (0 to 3). The mean pretreatment blood glucose of 33.2 +/- 23.3 mg/dL increased after treatment to 133.3 +/- 57.3 mg/dL. Qualitative level of consciousness increased from a mean of 1.26 +/- .96 to 2.42 +/- .94 and Glasgow Coma Score increased from a mean of 9.0 +/- 4.19 to 13.04 +/- 3.68. The mean time until response was 8.8 minutes in those who responded to both level of consciousness criteria 82% (41 of 50). Glucagon administered for hypoglycemia resulted in a glucose increase in 98% (49 of 50) with headache as the only side effect noted in 4% (two of 50) of patients (P less than .0001).

CONCLUSION

Glucagon is safe and effective therapy for hypoglycemia in the prehospital setting.

Sudden cardiac death due to hypoglycemia

We present a case of sudden cardiac death from hypoglycemia due to duodenal insulinoma in a previously healthy male. Cerebral neuroglycopenia symptoms were not evident and there was no knowledge of an existing insulinoma. It is suggested that glucose administration be considered in the setting of patients with suspected hyperinsulinemia and hypoglycemia. Rapid recognition and treatment could prevent cardiac irritability and death.