Hypoglycaemia: was associated with a high mortality rate

Clinical bottom line (level )

  1. In patients noted to be hypoglycaemic on biochemical testing, a high mortality rate was found (27% overall)
  2. In patients with hypoglycaemia noted on biochemical testing, the presence of risk factors was associated with an increase in mortality rates.
Fischer et al: N Engl J Med 1986; 315: 1245-1250
Expires March 2003

The study

Retrospective cohort study with unblinded, unobjective outcomes, ?adjusted for confounding factors, not validated in an independent set of patients.

Setting: University Medical Center in USA

94 patients (aged men age 51.1y (SE 2.8y), women age 46.3 (SE 2.8y), 61% female) hypoglycaemia (serum glucose <49 mg/dL) noted on biochemical testing for any reason

Excluded if
  • aged <17y
  • admitted to A&E with hypoglycaemia




    • multivariate analysis of risk factors

    followed for 6 months
    Outcomes studied:
  • Incidence of documented hypoglycaemia
  • mortality :risk factors were diabetes, insulin therapy, renal insufficiency, malnutrition, liver disease, infection

    • Factors are defined as; renal insufficiency defined as creatinine > 3 mg/dl; est. creatinine clearance <40 ml/min; on long-term dialysis: malnutrition defined as serum albumin <=2.5 mg/dl; body weight <70% ideal; chart describes 'cachexia'

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    Incidence of documented hypoglycaemia 6 months 94/7763 1.2%
    (1.0% to 1.5%)
    mortality 6 months 25/94 27%
    (18% to 36%)

    prognostic factor for
    mortality     		time to outcome control rate (%)
    0 risk factors ? 0/1
    (0%)
    1 risk factor ? 0/14
    (0%)
    2 risk factors ? 2/23
    (9%)
    3 risk factors ? 10/36
    (28%)
    4 risk factors ? 5/11
    (45%)
    5 risk factors ? 7/8
    (87%)

    Comments

    1. This is likely to be an underestimate of frequency of hypoglycaemia - the methodology would not identify cases diagnosed clinically or by fingerprick alone - and an overestimate of the mortality rates.
    2. Although a multivariate analysis was performed, no record is made of if the risk factor are independently significant

    Citation

    1. Fischer KF, Lees JA, Newman JH: Hypoglycemia in hospitalized patients, causes and outcomes.. N Engl J Med 1986; 315: 1245-1250
    Contributor: Matthew Taylor and Bob Phillips, March 1998
    Reviewer:

    Clinical Question.
    Patient In hospitalised adult in-patients
    Intervention or Exposure with hypoglycaemia
    Outcome is their a significant mortality rate?