Fabiola Maioli

Homocysteine and folate as risk factors for dementia and Alzheimer disease

BACKGROUND In cross-sectional studies, elevated plasma total homocysteine (tHcy) concentrations have been associated with cognitive impairment and dementia. Incidence studies of this issue are few and have produced conflicting results. OBJECTIVE We investigated the relation between high plasma tHcy concentrations and risk of dementia and Alzheimer disease (AD) in an elderly population. DESIGN A dementia-free cohort of 816 subjects (434 women and 382 men; mean age: 74 y) from an Italian population-based study constituted our study sample. The relation of baseline plasma tHcy to the risk of newly diagnosed dementia and AD on follow-up was examined. A proportional hazards regression model was used to adjust for age, sex, education, apolipoprotein E genotype, vascular risk factors, and serum concentrations of folate and vitamin B-12. RESULTS Over an average follow-up of 4 y, dementia developed in 112 subjects, including 70 who received a diagnosis of AD. In the subjects with hyperhomocysteinemia (plasma tHcy > 15 micromol/L), the hazard ratio for dementia was 2.08 (95% CI: 1.31, 3.30; P = 0.002). The corresponding hazard ratio for AD was 2.11 (95% CI: 1.19, 3.76; P = 0.011). Independently of hyperhomocysteinemia and other confounders, low folate concentrations (< or = 11.8 nmol/L) were also associated with an increased risk of both dementia (1.87; 95% CI: 1.21, 2.89; P = 0.005) and AD (1.98; 95% CI: 1.15, 3.40; P = 0.014), whereas the association was not significant for vitamin B-12. CONCLUSIONS Elevated plasma tHcy concentrations and low serum folate concentrations are independent predictors of the development of dementia and AD.

Blood inflammatory markers and risk of dementia: The Conselice Study of Brain Aging.

Incidence studies of blood inflammatory markers as predictors of dementia in older age are few and did not take into account hyperhomocysteinemia, although this condition is associated with both inflammation and increased risk of dementia. We investigated the relationships of baseline serum C-reactive protein (CRP), serum interleukin 6 (IL6), plasma alpha-1-antichymotrypsin, and hyperhomocysteinemia (defined as plasma total homocysteine>15 micromol/L) with risk of incident Alzheimers disease (AD) and vascular dementia (VaD) in a dementia-free Italian population-based elderly cohort (n=804, 53.2% women, mean age 74 years) with 4 years of follow-up. No inflammatory marker, alone or in combination, predicted AD risk whereas the combination of high CRP and high IL6 was associated with risk of VaD (HR, 2.56; 95%CI, 1.21-5.50) independently of socio-demographic confounders, traditional risk factors and hyperhomocysteinemia. By contrast, in the same model, hyperhomocysteinemia was independently associated with AD (HR, 1.91; 95%CI, 1.02-3.56) but not VaD risk. Blood inflammatory markers are associated with increased VaD risk but do not predict AD, which seems selectively associated with hyperhomocysteinemia.

Conversion of Mild Cognitive Impairment to Dementia: Predictive Role of Mild Cognitive Impairment Subtypes and Vascular Risk Factors

Mild cognitive impairment (MCI) is regarded as a precursor to dementia, but not all patients with MCI develop dementia. We followed up 165 elderly outpatients with MCI for a mean of 3 years. The aims were (1) to investigate the risk of conversion to dementia for different MCI subtypes diagnosed according to standardized criteria (amnestic; impairment of memory plus other cognitive domains; nonamnestic); (2) to assess whether the risk of conversion was affected by several established and emerging vascular risk factors. Forty-eight subjects (29%) converted to dementia, and the risk of conversion was doubled for amnestic MCI with respect to the other subtypes. Independently of MCI subtype, risk of conversion was associated with atrial fibrillation and low serum folate levels. Our results show that current diagnostic criteria for MCI define heterogeneous populations, but some potentially treatable vascular risk factors may be of help in predicting conversion to dementia.

Incidence and etiology of dementia in a large elderly Italian population

Objective: To estimate age- and sex-specific incidence of dementia, Alzheimer disease (AD), and vascular dementia (VaD) in the Conselice Study of Brain Aging, an Italian prospective population-based study, and to assess whether poor education is a risk factor for dementia. Methods: In 1999 to 2000, the baseline study identified a dementia-free cohort of 937 subjects aged 65 years and older who were reexamined in 2003 to 2004 using a two-phase procedure. Results: Information was obtained for 91% of the subjects at risk; 115 incident cases of dementia were identified. Incidence rates per 1,000 person-years were 37.8 (95% CI = 30.0 to 47.7) for dementia, 23.8 (95% CI = 17.3 to 31.7) for AD, and 11.0 (95% CI = 7.2 to 16.9) for VaD. This translates into more than 400,000 new cases of dementia expected per year in Italy. Increasing age was an independent risk factor for both AD and VaD. Poor education was an independent risk factor for AD but not VaD. Sex did not affect dementia risk. Conclusions: In this Italian population-based cohort, incidence of dementia increased with age, and Alzheimer disease (AD) was the most frequent type of dementia. Poor education was associated with a higher risk of AD. Our incidence rates are higher than previously reported in Italy, and provide new estimates for projection of future burden of disease in Italy.

Education, Occupation, and Prevalence of Dementia: Findings from the Conselice Study

Information about the epidemiology of dementia in Italy is still limited, although this cognitive disorder represents a serious public health concern. We estimated the prevalence of dementia and dementia subtypes in the elderly population of a Northern Italian municipality, Conselice, in the Emilia Romagna region (n = 1,016 subjects aged 65–97 years). The associations of dementia with two modifiable risk factors, education and occupation, were also evaluated. Overall dementia prevalence was 5.9% (95% confidence interval 4.3–7.8), exponentially increased with age, and was higher among women. Of the dementia cases, 50% were Alzheimer’s disease (AD), but an unusually high prevalence (45%) was found for vascular dementia (VD). After adjustment for age and gender, education but not occupation was associated with both AD and VD. This association could not be explained by occupation, life habits, and previous history of hypertension or cardiovascular disease.

Metabolic Syndrome Prevalence and prediction of mortality in elderly individuals

OBJECTIVE—Little is known about the prevalence of the metabolic syndrome among elderly people in Italy, its association with all-cause mortality, and whether measurement of serum C-reactive protein (CRP) and interleukin (IL)-6 affects this association. RESEARCH DESIGN AND METHODS—The baseline prevalence of metabolic syndrome, diagnosed according to the National Cholesterol Education Program (NCEP) criteria, and all-cause mortality at 4 years were recorded in an Italian population-based cohort (981 subjects, 55% women, aged 65–97 years). A Cox model adjusted for sociodemographic, lifestyle, and medical variables was used to investigate 1) whether metabolic syndrome was a predictor of mortality and 2) how the association was affected by baseline high CRP (>3 mg/l) and IL-6 (>1.33 pg/ml). RESULTS—Overall, metabolic syndrome prevalence was 27.2% [95% CI 24.0–30.5] and higher in women (33.3% [28.7–38.0]) than in men (19.6% [15.5–24.2]). During follow-up, 137 deaths occurred. Using the no metabolic syndrome/no high IL-6 group as the reference, mortality was not associated with the metabolic syndrome alone (multivariable-adjusted hazard ratio 1.24 [0.60–2.59]), only weakly associated with high IL-6 alone (1.66 [1.04–2.63]), but strongly associated with the concurrent presence of metabolic syndrome and high IL-6 (3.26 [2.00–5.33]). High CRP was not a mortality predictor (0.83 [0.58–1.20]) nor did it affect the association of the other variables with mortality. CONCLUSIONS—Metabolic syndrome by NCEP criteria is highly prevalent in the Italian elderly population. It is not itself associated with mortality but may improve the usefulness of IL-6 as a mortality predictor in older age.

Vitamin D, thyroid hormones and muscle mass influence natural killer (NK) innate immunity in healthy nonagenarians and centenarians

Increasing evidence has demonstrated that the immune system closely interacts with other physiological systems, whose communications are mediated by circulating cytokines and hormones. The aim of our study was to test whether the number and cytolytic activity of NK cells in a group of relatively healthy Italian nonagenarians and centenarians were affected by the modifications of endocrine, metabolic and functional parameters that occur during ageing. Because of the extreme age of the study population, a cross‐sectional analysis was performed. This study revealed that the group of oldest subjects with the highest number of NK cells and the best preserved cytolytic function also presented a preserved metabolism of thyroid hormones and vitamin D and integrity of muscle mass. In fact, the NK cell number and/or cytolytic activity of healthy subjects > 90 years old was positively associated with serum levels of vitamin D, while T3, FT4, i‐PTH hormones and lean body mass were associated only with NK cell number. In conclusion, our results stress the paramount importance of nutritional evaluation in the clinical assessment of elderly people.

Elevated plasma homocysteine levels in centenarians are not associated with cognitive impairment.

BACKGROUND Previous reports have shown elevated plasma total homocysteine (tHcy) levels in elderly person with impaired cognition. OBJECTIVE To study the association between cognitive status and plasma tHcy levels in centenarians. DESIGN Cross-sectional survey. SETTING Centenarians living in two northern Italian provinces. PARTICIPANTS Thirteen cognitively normal centenarians, ten cognitively impaired not-demented centenarians, and 34 demented centenarians with a clinical diagnosis of Alzheimers disease (AD). MEASUREMENTS Blood levels of homocysteines biological determinants vitamin B12, folate, and vitamin B6. RESULTS Elevated plasma tHcy levels (>17 micromol/l) were common in the general population (77% of normal centenarians, 100% of cognitively impaired not-demented centenarians, 82% of AD centenarians). Demented centenarians had the lowest folate serum levels. Low or borderline vitamin B12 serum levels (<221 pmol/l) and low vitamin B6 plasma levels (<11.7 nmol/l) were found in 33 and 66% of all centenarians independently of cognitive status. Among demented centenarians only plasma tHcy correlated inversely with both serum vitamin B12 and folate. No significant difference was found for plasma tHcy levels among the three diagnostic groups, even after adjusting for B vitamin levels. CONCLUSIONS Hyperhomocysteinemia is very common among centenarians, probably due to vitamin deficiencies, but does not seem to be associated with cognitive impairment.

Coeliac Disease in Patients with Autoimmune Thyroiditis

Background and Aims: The close association between coeliac disease and autoimmunity prompted us to perform an antibody screening for gluten-sensitive enteropathy in patients with autoimmune thyroid dysfunction. Methods: Sera from 220 patients with autoimmune thyroiditis, 50 euthyroid subjects with thyroid nodules and 250 blood donors were tested for IgA anti-tissue transglutaminase (anti-tTG) and antiendomysial antibodies (EmA). Results: IgA anti-tTG was positive in 7 patients with autoimmune thyroiditis, whereas IgA EmA was found only in 6 of them. Duodenal biopsy confirmed coeliac disease diagnosis disclosing marked and mild villous atrophy in 6 and 1 of them, respectively. All but 2 of the 7 coeliacs did not show any sign of malabsorption. All euthyroid controls were negative for IgA antibodies, whereas 1 blood donor, positive for both IgA anti-tTG and EmA, was found to be coeliac. The prevalence of coeliac disease in patients with autoimmune thyroiditis (3.2%) was significantly higher than that found in blood donors (0.4%) (p = 0.022, Fisher’s exact test). Conclusions: Antibody screening for coeliac disease should be included in the work-up of patients with autoimmune thyroiditis. Either IgA anti-tTG or EmA may be used, even though the former seems to be slightly more sensitive than the latter.

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.