Zinc and ageing: third Zincage conference

Serum Copper-to-Zinc Ratio and Risk of Chronic Obstructive Pulmonary Disease: A Cohort Study

PURPOSE

Serum copper (Cu), zinc (Zn), and Cu/Zn-ratio have emerged as ageing-related biomarkers. We sought to assess the association between Cu/Zn-ratio and chronic obstructive pulmonary disease (COPD) risk.

METHODS

Serum Cu and Zn were measured using atomic absorption spectrometry in 2,503 men aged 42-61 years.

RESULTS

During a median follow-up of 27.1 years, 210 COPD cases occurred. Serum Cu/Zn-ratio and Cu concentrations were linearly associated with COPD risk, whereas the relationship was curvilinear for Zn and COPD risk. A unit increase in Cu/Zn-ratio was associated with an increased COPD risk in multivariable analysis (hazard ratio, HR 1.81; 95% CI 1.08-3.05). The corresponding adjusted HR (95% CI) was 3.17 (1.40-7.15) for Cu. Compared to the bottom tertile of Zn, the HRs (95% CIs) were 0.68 (0.48-0.97) and 1.01 (0.73-1.41) for the middle and top tertiles of Zn, respectively.

CONCLUSIONS

Increased serum Cu/Zn-ratio and Cu concentrations were linearly associated with an increased COPD risk in men.

Serum copper-to-zinc ratio and risk of incident pneumonia in caucasian men: a prospective cohort study

Serum copper (Cu) and zinc (Zn), essential micronutrients that have important immunomodulatory and antimicrobial properties, are biomarkers of ageing. Serum Cu/Zn-ratio may be a more reliable marker for age-related degenerative conditions compared with serum Cu or Zn alone. We aimed to assess the association between Cu/Zn-ratio and the risk of incident pneumonia in a prospective cohort study. Serum levels of Cu and Zn were measured at baseline using atomic absorption spectrometry in 2503 men aged 42–61 years in the Kuopio Ischemic Heart Disease prospective cohort study. Hazard ratios (HRs) with confidence intervals (CIs) were calculated for incident pneumonia using Cox regression models. A total of 599 cases of pneumonia occurred during a median follow-up of 26.1 years. Serum Cu/Zn-ratio and Cu were each linearly associated with incident pneumonia. A unit increase in Cu/Zn-ratio was associated with an increased risk of pneumonia in analysis adjusted for potential confounders including C-reactive protein (HR 1.65; 95% CI 1.17–2.33). The corresponding adjusted HR (95% CI) was 2.04 (1.22–3.40) for serum Cu. The association between serum Zn and pneumonia was curvilinear. Compared to the bottom tertile of Zn, the multivariable adjusted HRs (95% CIs) for incident pneumonia were 0.68 (0.55–0.83) and 0.96 (0.79–1.16) for the middle and top tertiles of Zn, respectively. Further analysis in the same participants showed that Cu/Zn-ratio might be a stronger risk indicator for pneumonia than serum C-reactive protein. In middle-aged and older Finnish men, increased serum Cu/Zn-ratio and Cu concentrations are each linearly associated with an increased risk of incident pneumonia.

Molecular Mechanisms of Zinc as a Pro-Antioxidant Mediator: Clinical Therapeutic Implications

The essentiality of zinc as a trace mineral in human health has been recognized for over five decades. Zinc deficiency, caused by diet, genetic defects, or diseases, can cause growth retardation, delayed sexual maturation, depressed immune response, and abnormal cognitive functions in humans. Zinc supplementation in zinc-deficient individuals can overcome or attenuate these abnormalities, suggesting zinc is an essential micro-nutrient in the body. A large number of in vitro and in vivo experimental studies indicate that zinc deficiency also causes apoptosis, cellular dysfunction, deoxyribonucleic acid (DNA) damage, and depressed immune response. Oxidative stress, due to the imbalance of reactive oxygen species (ROS) production and detoxification in the anti-oxidant defense system of the body, along with subsequent chronic inflammation, is believed to be associated with many chronic degenerative diseases such as diabetes, heart diseases, cancers, alcohol-related disease, macular degenerative disease, and neuro-pathogenesis. A large number of experimental studies including cell culture, animal, and human clinical studies have provided supportive evidence showing that zinc acts as an anti-oxidative stress agent by inhibition of oxidation of macro-molecules such as (DNA)/ribonucleic acid (RNA) and proteins as well as inhibition of inflammatory response, eventually resulting in the down-regulation of (ROS) production and the improvement of human health. In this article, we will discuss the molecular mechanisms of zinc as an anti-oxidative stress agent or mediator in the body. We will also discuss the applications of zinc supplementation as an anti-oxidative stress agent or mediator in human health and disease.

Roles for endothelial zinc homeostasis in vascular physiology and coronary artery disease

The discovery of the roles of nitric oxide (NO) in cardiovascular signaling has led to a revolution in the understanding of cardiovascular disease. A new perspective to this story involving zinc (Zn) is emerging. Zn and its associated Zn transporter proteins are important for the integrity and functions of both the large conduit vessels and the microvascular resistance vessels. The Zn and NO pathways are tightly coordinated. Zn ions are required for the dimerization of endothelial nitric oxide synthase and subsequent generation of NO while generation of NO leads to a rapid mobilization of endothelial Zn stores. Labile Zn may mediate important downstream actions of NO including vascular cytoprotection and vasodilation. Several vascular disease risk factors (including aging, smoking and diabetes) interfere with Zn homeostatic mechanisms and both hypozincaemia and Zn transporter protein abnormalities are linked to atherosclerosis and microvascular disease. Some vegetarian diets and long-term use of certain anti-hypertensives may also impact on Zn status. The available evidence supports the existence of a Zn regulatory pathway in the vascular wall that is coupled to the generation and actions of NO and which is compromised in Zn deficiency with consequent implications for the pathogenesis and therapy of vascular disease.

Protein Poly(ADP-ribosyl)ation System: Changes in Development and Aging as well as due to Restriction of Cell Proliferation

It is well known that the number of dividing cells in an organism decreases with age. The average rate of cell division in tissues and organs of a mature organism sharply decreases, which is probably a trigger for accumulation of damage leading to disturbance of genome integrity. This can be a cause for the development of many age-related diseases and appearance of phenotypic and physiological signs of aging. In this connection, the protein poly(ADP-ribosyl)ation system, which is activated in response to appearance of various DNA damage, attracts great interest. This review summarizes and analyzes data on changes in the poly(ADP-ribosyl)ation system during development and aging in vivo and in vitro, and due to restriction of cell proliferation. Special attention is given to methodological aspects of determination of activity of poly(ADP-ribose) polymerases (PARPs). Analysis of relevant publications and our own data has led us to the conclusion that PARP activity upon the addition of free DNA ends (in this review referred to as stimulated PARP activity) is steadily decreasing with age. However, the dynamics of PARP activity measured without additional activation of the enzyme (in this review referred to as unstimulated activity) does not have such a clear trend: in many studies, the presented differences are statistically non-significant, although it is well known that the number of unrepaired DNA lesions steadily increases with aging. Apparently, the cell has additional regulatory systems that limit its own capability of reacting to DNA damage. Special attention is given to the influence of the cell proliferative status on PARP activity. We have systematized and analyzed data on changes in PARP activity during development and aging of an organism, as well as data on differences in the dynamics of this activity in the presence/absence of additional stimulation and on cellular processes that are associated with activation of these enzymes. Moreover, data obtained in different models of cellular aging are compared.

The contribution of dairy products to micronutrient intake in the Netherlands

OBJECTIVE

To assess the contribution of dairy products to the intake of various vitamins and minerals in several life stages in the Dutch population.

METHOD

Data from 3 Dutch Food Consumption Surveys and the Leiden Longevity Study were used to estimate the contribution of dairy products--as percentage of total intake--to the intake of iron, copper, selenium, zinc, calcium, folic acid, vitamin D, vitamin C, and vitamin B(12).

RESULTS

In young children, dairy products contributed substantially to the intake of calcium (73%), selenium (21%), iron (8%), zinc (39%), copper (12%), folic acid (24%), vitamin C (18%), vitamin D (16%), and vitamin B(12) (58%). Of all dairy products, milk contributed the most to the intake of these nutrients. In adults and elderly subjects, the contribution of dairy products to total micronutrient intake was 65%-68% for calcium, 18%-19% for selenium, 3%-4% for iron, 28%-31% for zinc, 6%-7% for copper, 17%-19% for folic acid, 10%-14% for vitamin C, 11%-16% for vitamin D, and 44%-46% for vitamin B(12). Milk as well as cheese contributed the most to the intake of these nutrients.

CONCLUSIONS

Dairy products are an important source of vitamins and minerals in the Dutch population. Dairy products, especially milk and cheese, contribute substantially to the intake of calcium, selenium, zinc, and vitamin B(12).

Immune response of 23-valent pneumococcal polysaccharide vaccinated elderly and its relation to frailty indices, nutritional status, and serum zinc levels

AIM

To detect the immunoglobulin M memory B cell population response following vaccination with the 23-valent pneumococcal polysaccharide vaccine and determine its relation to frailty indices, nutritional status, and serum zinc levels.

METHODS

A cross-sectional study was carried out in the outpatient geriatric clinic, Ain Shams University Hospital. It included 80 community-dwelling elderly, 32 male and 48 female. Each participant underwent vaccination with the 23-valent pneumococcal polysaccharide vaccine, comprehensive geriatric assessment, nutritional assessment with the DETERMINE check list, frailty indices assessment, and serum zinc level measurement. The percentage of immunoglobulin M memory B cells was evaluated before and 4 weeks after vaccination. Immune response was calculated as the difference between cell percentage before and after vaccination.

RESULTS

Before the vaccination, the immunoglobulin M memory B cell percentage was significantly lower among those eating fewer than two meals a day and taking three or more drugs a day; after vaccination significance was observed among those with tooth or mouth problems that make eating difficult. Immune response was significantly lower among those with tooth or mouth problems (P < 0.001), weight loss (P < 0.001), shrinking (P = 0.001), poor endurance (P = 0.04), multiple comorbidities (P = 0.013), and cognitive impairment (P = 0.001). Participants with immune response ≥10% showed significantly higher serum zinc levels compared to those with immune response <10% of increase in cell percentage.

CONCLUSION

Poor nutritional status, frailty and a lower zinc level impair the immunological response of elderly individuals.

Essential role of vitamin C and zinc in child immunity and health

With the progressive elimination of dietary protein-energy deficits, deficiencies of micronutrients are emerging as the limiting factors in ensuring children's optimal health. Data from several countries in Asia and Latin America indicate that deficiencies of vitamin C and zinc continue to be at alarming levels. This article reviews the roles of vitamin C and zinc in supporting children's growth and development, with a particular focus on the complementary roles they play in supporting immune functions and combating infections. The contemporary relevance of vitamin C and zinc deficiency in the Asian and Latin American regions, both undergoing a rapid nutritional transition, are also discussed. Overall, there is increasing evidence that deficiency of vitamin C and zinc adversely affects the physical and mental growth of children and can impair their immune defences. Nutrition should be the main vehicle for providing these essential nutrients; however, supplementation can represent a valid support method, especially in developing regions.

The nutritional pattern of frailty - Proceedings from the 5th Italian Congress of Endocrinology of Aging, Parma, Italy, 27-28 March 2009

Frailty has become one of the 'hot spots' in geriatric research. Frailty has multifactorial origin, and is regarded as a fundamental risk factor for deteriorating health status and disability in elderly people and is highly prevalent in the population above the age 65. It is estimates that prevalence rates up to 27% and pre-frailty rates up to 50% qualify for the term "epidemic". Although the role of nutritional deficiency in the development of age-related frailty was suggested long ago, research conducted in this area is relatively recent. The critical role of micronutrients in this context suggests the need to improve the quality of food eaten by elderly people whereas quantity of food appears to be less relevant. This review summarizes the recent literature on the nutritional pathways to frailty with particular focus on the effect of energy, protein and micronutrients.

The relationship between serum trace element levels and clinical parameters in patients with fibromyalgia

We examined the association between serum trace elements and clinical findings such as number of sensitive tender points, severity of fatigue and functional status in patients with fibromyalgia (FM). Thirty-two patients diagnosed as having FM according to the ACR 1990 criteria and 32 normal healthy controls (NHC) were included in this study. The demographic data, disease duration, number of tender points and accompanying symptoms (fatigue, sleep disorders, headache, paresthesia, irritable bowel syndrome, sicca symptoms, Raynaud's phenomena) of the patients were noted. Visual analog scale (10 cm) was implemented to estimate daily severity of pain and fatigue. Fibromyalgia impact questionnaire was used for functional assessment. Serum selenium (microg/dL) and serum zinc (microg/dL) levels were measured by atomic absorption spectrometer. Serum magnesium (mmol/L) level was measured by the original kits of Abbott Aeroset auto-analyzer. The mean age of patients in FM group and NHC were calculated as 42.9 (SD = 7.7) years and 41.3 (SD = 9.7) years, respectively. Serum levels of zinc (P = 0.001) and magnesium (P = 0.002) were significantly decreased by FM groups, whereas there was no considerable difference with selenium levels of both groups (P > 0.05). Association between serum zinc level and number of tender points (P = 0.008) and that between fatigue and magnesium level (P = 0.003) was found as meaningful. According to the results of this study, it was asserted that serum magnesium and zinc levels may play an important role in the pathophysiology of FM.

Age-dependent dichotomous effect of superoxide dismutase Ala16Val polymorphism on oxidized LDL levels

We investigated the association between superoxide dismutase (SOD) Ala16Val polymorphism and the levels of oxidized LDL lipoprotein-C (ox-LDL-C) in two age-different Greek cohorts. Four hundred fifteen middle-aged (n=147 females: 43.2+/-13 years, n=268 males: 43.3+/-14 years) Caucasian Greek subjects consisted the middle aged cohort. One hundred seventy five elderly (n=88 females: 79.9+/-4 years; n=87 males: 80.6+/-4 years) were selected from the elderly cohort. Genotype data were obtained for all of them. Multiple linear regression analysis, stratified by gender and adjusted for age, smoking habits and body mass index as covariates, showed higher ox-LDL-C levels for the middle aged men with the Val/Val genotype, compared to the other allele (Ala/Ala and Ala/Val) carriers (65.9+/-25.7 vs. 55.7+/-20.5 mg/dl; standardized beta coefficient=0.192, P=0.012). On the contrary, elderly women with the Val/Val genotype occurred with lower ox-LDL-C levels compared to the Ala/Ala or Ala/Val genotype (74.2+/-22.1 vs. 86.5+/-26.6 mg/dl; standardized beta coefficient= -0.269, P=0.015). The same trend was also recorded in elderly men, however without reaching statistical significance (standardized beta coefficient= -0.187, P=0.077). Moreover, elderly men and women with the Ala/Ala or Ala/Val genotype presented higher triglycerides levels compared to Val/Val (women: 145.2+/-68.7 vs. 114.3+/- 34.3 mg/dl, P= 0.027; men: 147.8+/-72.4 vs. 103.7 +/-38.0 mg/dl, P=0.002). Additionally, middle aged men with the Val/Val genotype had higher HDL-C levels compared to the Ala allele carriers. The results suggest that SOD Ala16Val polymorphism is an age-dependent modulator of ox-LDL-C levels in middle-aged men and elderly women.