Abstract |
Title: Metabolic factors and Mild Cognitive Impairment in elderly men
Background: The Metabolic Syndrome (MetS) is the clustering of five metabolic
factors (abdominal obesity, hypertriglyceridaemia, reduced HDL cholesterol,
hypertension and hyperglycemia). The presence of metabolic factors in middle-age
persons is associated with cognitive impairment, but studies in the elderly population
have reported conflicting results.
Aims and objectives: The aim of the present study is to examine whether there is a
link between metabolic factors and Mild Cognitive Impairment (MCI) in rural elderly
men. The potential correlations between MCI and metabolic factors with survival in
the oldest old people will also be explored. In addition, we will investigate whether
the results will be affected by the statistical manipulation of missing data.
Methodology: The sample included 131 men, 80-89 years old, who were members of
the Cretan cohort of the Seven Countries Study (response rate 94,9%), were examined
in 2000 and observed during the 10 years follow-up. Their cognitive function was
assessed via Mini Mental State Examination (MMSE) questionnaire and the score of
(≤23) was used as representative for the presence of MCI. There were correlations
between the Metabolic factors, the total z-score and the MCI via cross-sectional
(regression models) and then survival analysis techniques were used to examine the
correlations prospectively. A full case analysis was performed (88 men) and the
outcomes were compared to those in the available case analysis, with and without
mean imputation.
Results: The median age of the enrolled men who in the study was 84 years. (SD 2,
6). Forty percent (35 subjects) of the sample had MCI, 36% (32 subjects) had ≥ 3
metabolic factors. Many men had elevated blood pressure (89%) and increased waist
circumference (57%). In the cross-sectional analysis, we did not find any statistically
significant relationship between Metabolic factors (or z-score) and MCI. Only
10
elevated glucose levels had OR>1 (1,2, 95% CI= 0,4-1,3). The remaining 4 Metabolic
factors had OR between 0,6 and 0,8. Survival analysis demonstrated the potential
protective role of increased waist circumference (OR=0, 5, p=0,001) and decreased
HDL (OR=0, 5, p=0,062) to survival. Elevated blood glucose levels and the presence
of MCI seemed to increase the risk for all-cause mortality by 1,7 (95% CI= 1,02-3,03,
p=0,04) and 2 (95% CI= 1,2-3,0p=0,003)2 (p=0,003) and 1,7 (0,04), respectively. No
differences were observed regarding the handling of missing data.
Conclusions: In the present study, neither the individual metabolic factors, nor the
metabolic factor as a whole was found to be correlated with the presence of MCI in
the elderly. Nevertheless, survival seemed to be have been affected by the presence
of MCI, the increased waist circumference and the glucose concentration. Larger
studies are needed within this age group. If findings of this study are confirmed and
generalized, this could direct towards public health policy responses for the
prevention of MCI in elderly populations.
Keywords:
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