Alterations in glucose metabolism in patients with Alzheimer's disease.
OBJECTIVE
To determine the alterations in glucose metabolism that occur in patients with Alzheimer's Disease (AD).


METHODS
Cross-sectional comparison of AD and healthy controls.


METHODS
A University teaching hospital.


METHODS
Healthy controls (n = 14, BMI: 24.9 +/- 0.5 kg/M2, age 73 +/- 1 years) and patients with AD (n = 12, BMI: 23.9 +/- 1.0 kg/M2, age 72 +/- 1 years). All controls and patients with AD had a normal history and physical examination, a negative family history of diabetes, and took no medications.


METHODS
All patients and controls underwent an assessment of their dietary intake and physical activity, a 3-hour oral glucose tolerance test (OGTT), and a 2-hour hyperglycemic glucose clamp study.


RESULTS
Total caloric intake (AD: 27.1 +/- 1.3 kcal/kg/day;


METHODS
23.6 +/- 1.6 kcal/kg/day; P = ns) and intake of complex carbohydrates (AD: 5.9 +/- 0.4 kcal/kg/day;


METHODS
6.5 +/- 0.3 kcal/kg/day; P = ns) were not different between groups. Leisure time physical activity was greater in controls (AD: 2970 +/- 411 kcal/week;


METHODS
5229 +/- 864 kcal/week; P < 0.05). Patients with AD had higher fasting glucose (AD: 5.9 +/- 0.2 mmol/L;


METHODS
5.1 +/- 0.1 mmol/L; P < 0.01) and insulin (AD: 144 +/- 20 pmol/L;


METHODS
100 +/- 6 pmol/L; P < 0.05) values. In response to the OGTT, the area under the curve for glucose and insulin was similar in both groups. During the hyperglycemic clamp, steady-state glucose values were higher in the Alzheimer's patients (AD: 11.5 +/- 0.2 mmol/L;


METHODS
10.9 +/- 0.1 mmol/L, P < 0.01). First- and second-phase insulin responses were similar in each group. The insulin sensitivity index (units: mL/kg.min per pmol/L x 100), a measure of tissue sensitivity to insulin, was reduced in the patients with AD (AD: 0.59 +/- 0.06;


METHODS
0.79 +/- 0.07; P < 0.05).


CONCLUSIONS
We conclude that early AD is characterized by alterations in peripheral glucose metabolism, which may relate, in part, to alterations in physical activity.
Meneilly
G S
GS
Department of Medicine, University of British Columbia, Vancouver, Canada.
Hill
A
A
D000368:Aged; D000544:Alzheimer Disease / Q000378:metabolism*; D002149:Energy Intake; D005260:Female; D005947:Glucose / Q000378:metabolism*; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D008297:Male
D007328:Insulin; D005947:Glucose