Elevated plasma total homocysteine in centenarians

Homocysteine and age-associated disorders

There are numerous theories of aging, a process which still seems inevitable. Aging leads to cancer and multi-systemic disorders as well as chronic diseases. Decline in age- associated cellular functions leads to neurodegeneration and cognitive decline that affect the quality of life. Accumulation of damage, mutations, metabolic changes, failure in cellular energy production and clearance of altered proteins over the lifetime, and hyperhomocysteinemia, ultimately result in tissue degeneration. The decline in renal functions, nutritional deficiencies, deregulation of methionine cycle and deficiencies of homocysteine remethylation and transsulfuration cofactors cause elevation of homocysteine with advancing age. Abnormal accumulation of homocysteine is a risk factor of cardiovascular, neurodegenerative and chronic kidney disease. Moreover, approximately 50% of people, aged 65 years and older develop hypertension and are at a high risk of developing cardiovascular insufficiency and incurable neurodegenerative disorders. Increasing evidence suggests inverse relation between cognitive impairment, cerebrovascular and cardiovascular events and renal function. Oxidative stress, inactivation of nitric oxide synthase pathway and mitochondria dysfunction associated with impaired homocysteine metabolism lead to aging tissue degeneration. In this review, we examine impact of high homocysteine levels on changes observed with aging that contribute to development and progression of age associated diseases.

Homocysteine serum levels in diabetic patients with non proliferative, proliferative and without retinopathy

Homocysteine has been associated with extracellular matrix changes. The diabetic retinopathy is a neurovascular complication of diabetes mellitus and it is the leading cause of vision loss among working adults worldwide. In this study, we evaluate the role of homocysteine in diabetic retinopathy analyzing the plasma levels of homocysteine in 63 diabetic type 2 patients with nonproliferative retinopathy (NPDR), 62 patients with proliferative diabetic retinopathy (PDR), 50 healthy subjects used as control group, and 75 randomly selected patients.

Centenarians and supercentenarians: a black swan. Emerging social, medical and surgical problems

The Black Swan Theory was described by Nassim Nicholas Taleb in his book “The Black Swan”. This theory refers to “high-impact, hard-to-predict, and rare events beyond the realm of normal expectations”. According to Taleb’s criteria, a Black Swan Event is a surprise, it has a major impact and after the fact, the event is rationalized by hindsight, as if it had been expected. For most of human history centenarians were a rare and unpredictable phenomenon. The improvements of the social-environmental conditions, of medical care, and the quality of life caused a general improvement of the health status of the population and a consequent reduction of the overall morbidity and mortality, resulting in an overall increase of life expectancy. The study of centenarians and supercentenarians had the objective to consider this black swan and to evaluate the health, welfare, social and economic consequences of this phenomenon.

The oldest old: red blood cell and plasma folate in African American and white octogenarians and centenarians in Georgia

OBJECTIVE

To determine the overall folate status of a population-based multi-ethnic sample of octogenarians and centenarians and the specific dietary, demographic and physiological factors associated with observed abnormalities.

DESIGN

Population-based multiethnic sample of adults aged 80 to 89 and 98 and above.

SETTING

Northern Georgia, USA.

PARTICIPANTS

Men and women aged 80 to 89 (octogenarians, n = 77) and 98 and older (centenarians, n = 199).

ANALYSES

Wilcoxon rank sum tests, and Chi square and logistic regression analyses were used to examine associations of low and high folate status with hematological indicators and other variables of interest.

RESULTS

The prevalence of low red blood cell (RBC) folate was low overall, but tended to be higher in centenarians than in octogenarians (6.5% vs. 1.3%, p = 0.058; defined as RBC folate < 317 nmol/L). The risk of having lower RBC folate (< 25th vs. > 25th percentile for RBC folate for 60yr+ in NHANES 1999-2000) was greater in association with vitamin B12 deficiency (OR = 5.36; 95%CI: 2.87-10.01), African American race (OR = 4.29; 95%CI: 2.08-8.83), and residence in a skilled nursing facility (OR = 3.25; 95%CI: 1.56-6.78) but was not influenced by age, gender, B-vitamin supplement use, high/low food score or presence of atrophic gastritis. Combined high plasma folate and low vitamin B12 status was present in some individuals (n=11), but was not associated with increased prevalence of anemia or cognitive impairment in this study.

CONCLUSIONS

Low RBC folate status (< 317 nmol/L) was rare in this post folic acid fortification sample of octogenarians and centenarians. RBC folate status (< 25th percentile) was strongly associated with 1) vitamin B12 deficiency, which has strong implications for vitamin treatment, and 2) with being African American, suggesting racial disparities exist even in the oldest old.

The role of diabetes and aging in the determinism of hypertension and the related cerebrovascular complications

Epidemiological studies carried out on a large sample (3191 elderly and 640 centenarians) with identical criteria and applying the actual diagnostic standards, have evidenced a high, statistically significant prevalence of diabetes mellitus type 2 (DMT2) (18.84%) in the elderly, as compared to the centenarians (7.50%). This aspect is correlated with the major frequency of maturity onset diabetes in elderly (MODE), compared to the centenarians, correlated also to the mortality of diabetes mellitus (DM) of long duration. The DMT2 and the aging interact in the determinism of vascular alterations, i.e., of the hypertension, and related cardio-cerebrovascular complications. The most frequently occurring hypertension in both the elderly and centenarians was always the systolic-isolated one. The prevalence of hypertension and acute myocardial infarction (AMI) was statistically significantly higher in diabetics, compared to the normoglycemic patients, in both the elderly and the centenarians. In addition, in a group of 914 elderly patients, being diabetics or normoglycemic at the start of the studies, but having neither AMI nor stroke at the baseline studies, after 5 years, these complications were more prevalent, significantly in statistical terms, in the diabetic subjects, compared to the normoglycemic ones. The increase of life-span causes an increase of the age when the aging phenomena appear, resulting in that the equal-age elderly people today are of better clinical conditions, compared to the previous periods. The increased life span with a consequent progressive aging of the population causes a worse general clinical state of the elderly population, characterized by polypathologies, frailty, and appearance of cognitive deficits or incapabilities for performing manual or instrumental activities.

Nutrition in centenarians

The oldest old are among the fastest growing segment of the population and it is important to understand not only the influence of modifiable lifestyle factors such as diet and nutrition on the achievement of exceptional longevity but also the role, if any, of these factors on maintaining optimal cognitive, mental and physical health into advanced age. This review summarizes studies of dietary intake and patterns of long-lived peoples and presents current knowledge of nutritional status of centenarians as determined with nutritionally relevant biomarkers, providing information on comparative levels of the various biomarkers between centenarians and older adult controls and on the prevalence and predictors of nutritional deficiencies in centenarians. The studies indicate that BMI and nutritional status as indicated by circulating levels of antioxidant vitamins, vitamin B12, folate, homocysteine and 25(OH) vitamin D of centenarians are quite heterogeneous and influenced by region of residency and many of the demographic, dietary and lifestyle factors that influence nutritional status in other older adults. While many of the studies have been small, convenience samples of relatively healthy community-dwelling centenarians, a few have population-based or included participants of varying cognitive functioning. These and future studies examining associations between nutritional status and cognitive, mental and physical function should be instrumental in determining the role of nutrition in promoting longevity and improving the quality of life in these exceptional survivors.

Elevated levels of plasma homocysteine in postmenopausal women in Burkina Faso

BACKGROUND

Low levels of plasma homocysteine have been found in children and adult populations living in Burkina Faso in association with a low prevalence of coronary heart disease.

METHODS

Based on this finding, the levels of plasma homocysteine and other thiols (cysteine, cysteinylglycine, glutathione) in postmenopausal women living in Burkina Faso were evaluated with the aim of investigating whether age and life conditions influence plasma homocysteine and other thiol levels.

RESULTS

It was found that in older postmenopausal women the mean level of homocysteine was higher (16.4+/-6.6 micromol/L) than in fertile women (6.8+/-1.2 micromol/L) and that this increase was correlated with cysteine levels (166.6+/-44.6 micromol/L). While the glutathione level in postmenopausal women was lower (3.6+/-2.3 micromol/L) compared with fertile women (7.0+/-1.7 micromol/L), cysteinylglycine levels were within the normal range (29.9+/-9.3 micromol/L). No correlation was found between homocysteine levels and serum folate, vitamin B(12), vitamin B(6), cystatin C and serum creatinine levels. The older the women were, the higher were their plasma homocysteine levels: levels up to 20.2+/-9.1 micromol/L were found in those >70 years old.

CONCLUSIONS

The elevated levels of homocysteine in the postmenopausal women of Burkina Faso must be viewed as a characteristic of older age and its metabolic consequences.

Homocysteine, vitamin B12 and folate in vascular dementia and in Alzheimer disease

The association between elevated plasma levels of homocysteine (Hcy) and nutritional status has been shown in Alzheimer disease (AD) patients and also in vascular dementia (VaD). Moreover, a previous study provided evidence that the relation between a high Hcy level and low vitamin B12 and folate levels in AD patients is due to biochemical damage, rather than a nutritional deficit. The purpose of this study was to investigate the relationship between plasma Hcy levels and vitamins involved in its metabolism in AD and VaD. Twenty-two VaD patients, 22 AD patients and 24 healthy subjects were studied for Hcy, vitamin B12, vitamin B6 and folate. All patients and control subjects were comparable for age, educational level, nutritional and socioeconomic status. None of them showed macrocytic anemia or impaired renal function. Hcy was significantly increased in VaD patients (26.0 +/- 6.58 micromol/l) as compared to controls (10.7 +/- 3.0 micromol/l) and AD patients (22.3 +/- 4.51 micromol/l; p<0.001); however, AD patients also showed increased levels of Hcy. Folates were significantly reduced in both VaD (10.8 +/- 2.81 nmol/l) and AD (10.0 +/- 2.72 nmol/l; p<0.001) patients, while vitamin B12 showed significantly reduced levels only in AD patients (392.1 +/- 65.32 pmol/l; p=0.02). Vitamin B6 was not significantly different in the three groups. Increased levels of Hcy associated with low vitamin B12 plasma levels were found only in AD patients. This observation led us to consider that vitamin B12 metabolism does not represent the direct consequence of the nutritional status and suggests that neuronal damage results in a functional vitamin B12 deficiency, as emphasized by recent reports. New therapeutic strategies are necessary, considering that available pharmaceutical forms of vitamin B12 are not utilized by neurons in oxidative stress conditions.