Oxidative stress and dementia in oldest-old subjects

Homocysteine and cognitive function in healthy elderly community dwellers in Italy

BACKGROUND

Elevated plasma total homocysteine (tHcy) concentrations are common in the elderly and have been suggested to be a risk factor for dementia.

OBJECTIVE

In an elderly population, we examined the relation between plasma tHcy and scores on the Mini-Mental State Examination (MMSE), a commonly used screening measure of cognitive impairment in general practice.

DESIGN

Fasting plasma tHcy concentrations were measured in 650 healthy, cognitively normal Italian community dwellers aged > or = 65 y (x +/- SD: 72.8 +/- 6.0 y). Socioeconomic status; serum folate, vitamin B-12, and creatinine; other potential dietary and lifestyle determinants of tHcy; and conventional vascular disease risk factors were also assessed.

RESULTS

Subjects with MMSE scores of 26-28 had higher plasma tHcy concentrations (12.7 micromol/L; range: 12.2-13.2 micromol/L) than did those with scores > 28 (11.9 micromol/L; 11.4-12.3 micromol/L; P < 0.01). Subjects with scores of 24-25 had higher plasma tHcy concentrations (14.5 micro mol/L; 13.5-15.6 micromol/L) than did subjects with scores of 26-28 (P < 0.01) or > 28 (P < 0.001). The risk of hyperhomocysteinemia (plasma tHcy > 15 micromol/L) was higher in subjects with scores of 24-25 (odds ratio: 3.81; 95% CI: 1.9, 7.5) or 26-28 (odds ratio: 1.96; 95% CI: 1.3, 3.0) than in those with scores > 28. The results did not change after adjustment for conventional vascular risk factors and for age, medical, dietary, and lifestyle determinants of plasma tHcy.

CONCLUSION

Elevated plasma tHcy has an independent, graded association with concurrent cognitive impairment as measured with the MMSE in healthy elderly community dwellers.

Dehydroepiandrosterone-sulfate serum levels and common age-related diseases: results from a cross-sectional Italian study of a general elderly population

The association of low serum dehydroepiandrosterone sulfate (DHEAS) levels with age, lifestyle, general health status indicators, and specific diseases was investigated in 436 men and 544 women of 65-97 yr old. In both sexes low serum DHEAS levels were associated with age, alcohol intake, number of current medications, and decreased thyroid function. Low DHEAS was also associated with low serum albumin in men and low systolic blood pressure in women. Compared to healthy men (n=106) age-adjusted serum DHEAS levels were significantly lower in men with atrial fibrillation, chronic obstructive lung disease, dementia, parkinsonism, cancer, diabetes, hypothyroidism, and in institutionalized men. Compared to healthy women (n=100) age-adjusted serum DHEAS levels were significantly lower in women with occlusive arterial disease, chronic obstructive lung disease, and osteoporosis. After controlling for differences in lifestyle and general health status parameters, low DHEAS levels remained statistically associated only with atrial fibrillation in men and osteoporosis in women, and it cannot be excluded that these association were spurious, due to multiple comparisons. These data suggest that in elderly people low serum DHEAS levels are more a non-specific indicator of aging and health status than a risk indicator of specific diseases.