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Biomedical subjects

Edward P Norkus

Publications and source records attributed to Edward P Norkus.

At least 19 recordsLinked to original sources
PubMed2006

Anemia increases risk for falls in hospitalized older adults: an evaluation of falls in 362 hospitalized, ambulatory, long-term care, and community patients.

OBJECTIVE: The objective of this study was to determine if a relationship exists between the presence of anemia and the occurrence of falls during hospitalization in ambulatory older adults from long-term care and community settings. All individuals were hospitalized for acute conditions not related to a fall. PARTICIPANTS: Three hundred sixty-two hospitalized, ambulatory older (59-104 years) adults. MEASUREMENTS: Laboratory values (hemoglobin [Hb], hematocrit [Hct]), routine laboratory tests, pertinent medical history, and demographics. RESULTS: Ambulatory hospitalized patients who fell were compared to controls (no falls during hospitalization) of similar age (P = .283) and gender distribution (P = .554). Patients who fell had significantly lower Hb (P < .00005), lower Hct (P < .00005) and were more likely to be anemic (56% vs 38%, P = .001) than controls. A logistic regression model examined the effect of Hb level and anemia on falls and included the covariates of age, gender, place of residence, and race. The model described a 22% decreased risk of falls for every 1.0 g/dL increase in Hb (P < .0005) and an overall 1.9-fold increased risk of falls in anemic patients (P < .001). Patient age, gender, and place of residence were not related to the risk of falls during hospitalization. CONCLUSIONS: These findings suggest a potentially important link between anemia and the risk of falls during hospitalization in ambulatory older patients. Further studies are needed to determine if the risk of falls can be modified by correction of anemia and to determine the applicability of these findings to older adults in different settings.

Academic Medical Centers↗
PubMed2006

Relations of glycemic index and glycemic load with plasma oxidative stress markers.

BACKGROUND: Recent data suggest that acute hyperglycemia may increase in vivo free radical production. This increased production has been implicated in many disease processes. OBJECTIVE: The objective was to investigate whether a diet with a high glycemic index (GI) or glycemic load (GL) is associated with greater oxidative stress as measured by 2 lipid peroxidation markers, malondialdehyde (MDA) and F2-isoprostanes (IsoPs). DESIGN: Plasma MDA and IsoP concentrations were measured in 292 healthy adults, and dietary GI and GL were assessed by using a validated food-frequency questionnaire. Cross-sectional associations between GI, GL, and the 2 markers were examined by using multiple regression techniques with adjustment for potential confounding variables. RESULTS: Dietary GI was positively associated with both plasma MDA and IsoPs. The mean multivariate-adjusted MDA concentrations increased from 0.55 to 0.73 micromol/L as GI increased from the lowest to the highest quartile (P for trend = 0.02); the corresponding IsoP concentrations increased from 0.034 to 0.040 ng/mL (P for trend = 0.03). GL was positively associated with both MDA and IsoPs, but the linear relation was significant only for MDA. In addition, a marginally significant interaction between overall GI and body mass index (BMI; in kg/m2) for plasma MDA was observed (P = 0.09). The positive association between overall GI and MDA was stronger in those with a BMI < 26.5 than for those with a BMI > or = 26.5. CONCLUSIONS: Chronic consumption of high-GI foods may lead to chronically high oxidative stress. A low-GI diet, not a low-carbohydrate diet, appears to be beneficial in reducing oxidative stress.

Adolescent↗
PubMed2006

Relationship between seminal ascorbic acid and sperm DNA integrity in infertile men.

Ascorbic acid has recently been reported to protect sperm DNA from the damage induced by exogenous oxidative stress in vitro. But, there is no report on seminal ascorbic acid and sperm DNA fragmentation in infertile men. In this study, we asked whether sperm DNA damage correlates with seminal ascorbic acid levels. Sperm DNA fragmentation index (DFI) was analysed in 75 men by flow cytometry after acridine orange staining. We also measured the levels of seminal plasma ascorbic acid and total antioxidant capacity. Abnormal sperm DNA integrity (DFI >or= 30%) was observed in 12% of the patients with normal semen parameters and in 52% of the patients with abnormal semen parameters. There were significant correlations between the level of DFI and conventional semen parameters including sperm count, motility and morphology (r = -0.29, -0.55 and -0.53 respectively; p < 0.05). Seminal ascorbic acid level was significantly lower in the patients with leucospermia than the patient with normal semen parameters. Interestingly, a significantly greater percentage of men with abnormal DFI were observed in the patients with low levels of seminal ascorbic acid compared with those with normal or high levels of ascorbic acid (59% vs. 33%, p < 0.05). Men with insufficient seminal ascorbic acid frequently have sperm DNA damage.

Adult↗
PubMed2005

To anticoagulate or not to anticoagulate? A common dilemma for the provider: physicians' opinion poll based on a case study of an older long-term care facility resident with dementia and atrial fibrillation.

OBJECTIVE: Anticoagulation therapy is an acceptable strategy for the prevention of thromboembolic events in the presence of atrial fibrillation. However, this strategy is controversial in older subjects particularly in the presence of dementia. We conducted an opinion poll regarding the decision to anticoagulate or not among physicians in practice and in various levels of training (residents and fellows) that was based on a specific, yet not unusual, case scenario in the nursing home. SETTING: A university teaching hospital in the Bronx, NY. METHODS: A survey questionnaire was distributed to physicians to solicit opinions on the decision to anticoagulate based on an actual case from a LTCF and the results were analyzed. RESULTS: One hundred seven completed surveys were returned from 49 residents, 20 fellows, and 38 attending physicians. The majority (85%) felt that long-term anticoagulation therapy was not indicated in the case patient. However, most (88%) felt they would provide an antiplatelet agent, with the choice being 78% aspirin, 20% clopridogel, and 2% aspirin-dipyridamole. The most cited reasons for not providing anticoagulation were risk of falls (98%), dementia (40%), and short life expectancy (32%). However, 92% of respondents felt that the patient was a candidate for short-term anticoagulation therapy. Interestingly, the choices (yes, no, uncertain) to the questions were similar for all physicians irrespective of their level of training or years in practice (or faculty) after training. CONCLUSIONS: Although long-term anticoagulation for thromboembolic events in atrial fibrillation is considered beneficial, recent reports suggest that warfarin is underused in older adults, especially in the long-term care setting. Our physician poll, based on a specific case scenario, is consistent with this opinion as reflected by both trainees and practicing physicians. While there are absolute and relative contraindications to the use of long-term warfarin, decisions should be individualized and based on risks, benefits, and quality of life of the resident.

Accidental Falls↗
PubMed2005

The effects of vitamin C supplementation on serum concentrations of uric acid: results of a randomized controlled trial.

OBJECTIVE: Reductions in serum uric acid levels are clinically relevant. Previous studies have suggested a uricosuric effect of vitamin C. Whether vitamin C reduces serum uric acid is unknown. We undertook this study to determine the effects of vitamin C supplementation on serum uric acid concentrations. METHODS: The study was a double-blinded placebo-controlled randomized trial conducted in research units affiliated with an academic institution. Study participants were 184 nonsmokers, randomized to take either placebo or vitamin C supplements (500 mg/day) for 2 months. RESULTS: At the end of the study period, serum uric acid levels were significantly reduced in the vitamin C group (mean change -0.5 mg/dl [95% confidence interval -0.6, -0.3]), but not in the placebo group (mean change 0.09 mg/dl [95% confidence interval -0.05, 0.2]) (P < 0.0001). The same pattern of results was evident in subgroups defined by age, sex, race, body mass index, chronic illness, diuretic use, and quartiles of baseline serum ascorbic acid levels. In the subgroups, from the lowest to the highest quartile of baseline serum uric acid, net mean changes (95% confidence intervals) in serum uric acid with vitamin C supplementation were -0.4 (-0.8, 0.01), -0.5 (-0.9, -0.2), -0.5 (-0.8, -0.2), and -1.0 (-1.6, -0.4) mg/dl (P = 0.06, 0.005, 0.003, and 0.002, respectively). Compared with placebo, vitamin C increased the estimated glomerular filtration rate. CONCLUSION: Supplementation with 500 mg/day of vitamin C for 2 months reduces serum uric acid, suggesting that vitamin C might be beneficial in the prevention and management of gout and other urate-related diseases.

Adult↗
PubMed2005

Plasma lycopene, other carotenoids, and retinol and the risk of cardiovascular disease in men.

BACKGROUND: Emerging evidence suggests a possible role of lycopene in the primary prevention of cardiovascular disease (CVD). OBJECTIVE: We examined whether plasma lycopene concentrations in the Physicians' Health Study were associated with CVD in a prospective, nested, case-control design. DESIGN: Baseline blood samples were collected starting in 1996. During a mean follow-up of 2.1 y, we identified 499 cases of CVD (confirmed myocardial infarction, stroke, CVD death, or revascularization procedures) and an equal number of men free of CVD and matched for age (x: 69.7 y), follow-up time, and smoking status. We collected self-reported coronary disease risk factors and measured plasma carotenoids, retinol, lipids, and C-reactive protein. RESULTS: In matched analyses with additional adjustment for plasma total cholesterol and randomized treatment, the relative risks (RRs) of CVD for men in the lowest to highest quartiles of plasma lycopene were 1.00 (reference), 0.92, 1.04, and 0.95 (P for linear trend = 0.93). With multivariate adjustment, the RRs of total CVD were 1.00 (reference), 1.08, 0.94, and 1.03 (P for linear trend = 0.98). For important vascular events (241 cases), excluding revascularization procedures, the multivariate RRs remained nonsignificant (P for linear trend = 0.50). Adding plasma carotenoids, lipids, or C-reactive protein to multivariate models had a minimal effect on the RRs of total CVD for plasma lycopene. Compared with lycopene, higher concentrations of plasma lutein/zeaxanthin and retinol suggested a moderate increase in CVD risk, whereas no association was found for beta-cryptoxanthin, alpha-carotene, and beta-carotene. CONCLUSIONS: Higher plasma lycopene concentrations were not associated with the risk of CVD in this study of older men. Further evaluation in diverse populations is necessary.

Aged↗
PubMed2005

Dietary and plasma lycopene and the risk of breast cancer.

Lycopene is potentially effective in the prevention of breast cancer from laboratory and observational studies. Among 39,876 women initially free of cardiovascular disease and cancer, we first conducted a prospective cohort study of dietary lycopene and its food sources. Participants completed a baseline food frequency questionnaire and provided self-reports of breast cancer risk factors. Dietary lycopene levels were divided into quintiles, and lycopene food sources were categorized. During 9.9 years of follow-up, 1,076 breast cancer cases were confirmed by medical record review. In a nested case-control study, we then identified 508 breast cancer cases and 508 controls matched by age, smoking, and follow-up time. Plasma lycopene and other carotenoids were measured. In the prospective cohort study, women with increasing quintiles of dietary lycopene had multivariate relative risks (RR) of breast cancer of 1.00 (ref), 0.95, 1.00, 1.10, and 1.00 (P, linear trend = 0.71). Women consuming <1.5, 1.5 to <4, 4 to <7, 7 to <10, and > or =10 servings/week of tomato-based products had RRs of 1.00 (ref), 1.00, 1.20, 1.18, and 1.16 (P, linear trend = 0.11). No individual lycopene food sources were associated with breast cancer. In the nested case-control study, women in increasing quartiles of plasma lycopene had multivariate RRs of breast cancer of 1.00 (ref), 0.95, 1.15, and 0.93 (P, linear trend = 0.86). The stepwise addition of individual plasma carotenoids did not impact the RRs for plasma lycopene, nor were other carotenoids associated with breast cancer. In conclusion, neither higher dietary nor plasma lycopene levels were associated with a reduced risk of breast cancer in middle-aged and older women.

Aged↗
PubMed2005

Vitamin D deficiency in community older adults with falls of gait imbalance: an under-recognized problem in the inner city.

INTRODUCTION: Recent reports suggest that vitamin D deficiency is both under-recognized and undertreated in the geriatric population. In particular, older adults with unexplained pain, falls, and gait disorders often may have osteomalacia from vitamin D deficiency. Currently, older adults are not screened for vitamin D status even when clinical skin suggest deficiency. Our pilot study determined the vitamin D status in older, inner city community adults with features suggestive of vitamin D deficiency. METHODS: The study was prospective and observational. Community-dwelling adults (> 60 years) from our ambulatory clinic or in-patient geriatric program, with features compatible with vitamin D deficiency (history of falls, gait imbalance, unexplained musculoskeletal pain, and/or fractures), were enrolled. IRB approval and signed informed consents were obtained. Following a history and physical exam, blood samples for vitamin D assay and routine chemistries were obtained. Additional information was collected on age, gender, race, dairy product intake, calcium and/or vitamin D supplement use, weekly sunlight exposure, season of exam (May-October vs. November-April), prior falls and fractures, musculoskeletal pain, and gait disturbances. RESULTS: Data were obtained from 48 patients (32F and 16M), mean age of 79 +/- 9 (SD) years (range 60-95). Seventy-seven percent of enrollees had gait disturbances, 77% had a history of falls, 29% had previous fractures and 6% had unexplained pain; 79% consumed milk daily, 25% took calcium supplements and 21% used vitamin D supplements (in a multivitamin or calcium supplement). Self-reported weekly exposure to sunlight ranged from 0 to 42 hours (clothing amount was highly variable). Fifty-four percent of this sample had sub-normal vitamin D status (serum vitamin D < 20 ng/mL). Patient age (P = 0.2287), gender (P=0.9270), exposure to sunlight (P=0.3493), season (P=0.573), and dairy intake (P = 0.735) were not associated with vitamin D status. However, 80% of vitamin D supplement users versus 37% of non-users had normal vitamin D status (P = 0.029) and 75% of calcium supplement users versus 36% of non-users had normal vitamin D status (P = 0.042). A logistic regression model determined that the use of vitamin D or calcium supplements decreased the risk of low vitamin D status by 94% and 93% (P = 0.009 and P = 0.010, respectively). CONCLUSION: In this pilot study of older adults with gait imbalance and falls, vitamin D deficiency (< 20 ng/mL) was observed in 54% of patients tested and previously unrecognized. Higher serum vitamin D levels appeared related to the use of vitamin D (in multivitamin or calcium supplements) suggesting that deficiency may be preventable and easily treated. As vitamin D deficiency is associated with substantial disability, the need for increased awareness to screen and prevent this disorder is evident.

Accidental Falls↗
PubMed2005

Does anemia matter? Anemia, morbidity, and mortality in older adults: need for greater recognition.

Anemia is common and under recognized in older adults and associated with increased morbidity and mortality. Estimates of prevalence of anemia in older adults vary considerably based on the setting, gender, age and definition used and likely to increase further based on aging trends. Rather than simply a consequence of aging, anemia is a marker of underlying disease, requiring investigation for an etiology. A cause is discernible in at least two-thirds of cases; management involves addressing the underlying disease process, replacement of deficient nutrients or the use of erythropoietic factors.

Adaptation, Physiological↗
PubMed2004

Plasma C-reactive protein concentrations in active and passive smokers: influence of antioxidant supplementation.

OBJECTIVE: C-reactive protein (CRP) may directly affect the progression of atherosclerosis, and therefore, may be a target for reducing disease risk. The objective was to determine whether antioxidant supplementation reduces plasma CRP in active and passive smokers. DESIGN: Randomized, double-blind, placebo-controlled, parallel group trial with 2 months exposure to study supplements. SETTING: Berkeley and Oakland, California. SUBJECTS: Healthy adult men and women, consuming <4 daily servings of fruits and vegetables, and who were actively or passively exposed to cigarette smoke. Analysis was limited to participants with detectable baseline CRP concentrations and no evidence of inflammation associated with acute illness at baseline or follow-up as reflected in CRP elevations (> or =10.0 mg/L). A total of 1393 individuals were screened, 216 randomized, 203 completed the study, and 160 were included in the analysis. INTERVENTIONS: Participants were randomized to receive a placebo or vitamin C (515 mg/day) or antioxidant mixture (per day: 515 mg vitamin C, 371 mg alpha-tocopherol, 171 mg gamma-tocopherol, 252 mg mixed tocotrienols, and 95 mg alpha-lipoic acid). MEASURES OF OUTCOME: Change in plasma CRP concentration. RESULTS: Vitamin C supplementation yielded a 24.0% reduction (95% confidence interval, -38.9% to -5.5%, p = 0.036 compared to control) in plasma CRP, whereas the antioxidant mixture and placebo produced a nonsignificant 4.7% reduction (-23.9% to 19.3%) and 4.3% increase (-15.1% to 28.2%), respectively. Results were adjusted for baseline body mass index and CRP concentrations. CONCLUSIONS: Plasma CRP itself may serve as a potential target for reducing the risk of atherosclerosis, and antioxidants, including vitamin C, should be investigated further to confirm their CRP-lowering and anti-inflammatory effects.

Antioxidants↗
PubMed2004

Plasma lycopene, other carotenoids, and retinol and the risk of cardiovascular disease in women.

BACKGROUND: Growing evidence suggests that lycopene has significant in vitro antioxidant potential. Lycopene has rarely been tested in prospective studies for its role in cardiovascular disease (CVD) prevention. OBJECTIVE: We examined the association between plasma lycopene and the risk of CVD in middle-aged and elderly women. DESIGN: A prospective, nested, case-control study was conducted in 39 876 women initially free of CVD and cancer in the Women's Health Study. Baseline blood samples were collected from 28 345 (71%) of the women. During a mean of 4.8 y of follow-up, we identified 483 CVD cases and 483 control subjects matched by age, smoking status, and follow-up time. Plasma lycopene, other carotenoids, retinol, and total cholesterol were measured. RESULTS: In analyses matched for age and smoking, with adjustment for plasma cholesterol, the relative risks (RRs) and 95% CIs of CVD in increasing quartiles of plasma lycopene were 1.00 (referent), 0.78 (95% CI: 0.55, 1.11), 0.56 (0.39, 0.82), and 0.62 (0.43, 0.90). In multivariate models, the RRs were 1.00 (referent), 0.94 (0.60, 1.49), 0.62 (0.39, 1.00), and 0.67 (0.41, 1.11); those in the upper compared with the lower half of plasma lycopene had an RR of 0.66 (0.47, 0.95). For CVD, exclusive of angina, women in the upper 3 quartiles had a significant multivariate 50% risk reduction compared with those in the lowest quartile. The stepwise addition of individual plasma carotenoids did not affect the RRs. CONCLUSIONS: Higher plasma lycopene concentrations are associated with a lower risk of CVD in women. These findings require confirmation in other cohorts, and the determinants of plasma lycopene concentrations need to be better understood.

Aged↗
PubMed2003

Vitamin E therapy in IgA nephropathy: a double-blind, placebo-controlled study.

IgA nephropathy is the world's most common primary glomerulonephropathy. Recent evidence in a rat model implicated excessive production of oxygen-free radicals in the pathogenesis and suggested that vitamin E-treatment ameliorated progression. We studied this antioxidant therapy on the glomerular filtration rate (GFR), proteinuria and hematuria in biopsy-proven IgA nephropathy in children. The duration of treatment or placebo was 2 years, with vitamin E treatment consisting of 400 IU/day in children weighing <30 kg, and twice that dose for those >30 kg. We measured GFR at entry, midpoint and exit. At baseline and at 4-month intervals after randomization, urinary protein/creatinine ratios and urinalysis were examined. The mixed model procedure with log transformation was used in data analysis to test treatment difference as well as the potential time effect. Fifty-five patients were randomized and 38 completed at least 1 year of follow-up. At entry, the clinical characteristics were not different between the treatment and placebo groups. There was a trend toward better preservation of GFR in vitamin E-treated versus placebo patients, 127+/-50 vs. 112+/-31 ml/min/1.73 m(2), respectively ( P=0.09). The urinary protein/creatinine ratio was significantly lower in the vitamin E-treated group vs. placebo; 0.24+/-0.38 vs. 0.61+/-1.37 ( P<0.013). However, there was no difference in the prevalence of hematuria between the groups. Vitamin E treatment in our study patients was associated with significantly lower proteinuria, but no effect on hematuria. While there was a trend toward stabilization of GFR in the vitamin E-treated patients, long-term treatment and follow-up are needed to determine whether antioxidant therapy is associated with preservation of renal function in IgA nephropathy.

Adolescent↗
PubMed2003

Prospective study of antioxidant micronutrients in the blood and the risk of developing prostate cancer.

Antioxidant micronutrients may have chemopreventive effects. The authors examined the associations between prediagnostic blood levels of micronutrients and prostate cancer risk in two nested case-control studies of 9,804 and 10,456 male residents of Washington County, Maryland, who donated blood in 1974 (CLUE I) and 1989 (CLUE II), respectively. Until 1996, 182 men for whom adequate serum remained for assays in the CLUE I cohort and 142 men in the CLUE II cohort developed prostate cancer. Each case was matched with two controls by age, gender, race, and date of blood donation. In both cohorts, cases and controls had similar concentrations of alpha-carotene, beta-carotene, total carotene, beta-cryptoxanthin, lutein, lycopene, retinol, and ascorbic acid; serum alpha-tocopherol was weakly associated with prostate cancer risk. Higher retinyl palmitate concentrations were associated with a lower risk in CLUE I but not CLUE II. In CLUE I, cases had lower concentrations of gamma-tocopherol than did controls (p = 0.02), but no dose-response trend was observed. A strong inverse association between gamma-tocopherol and prostate cancer risk was observed in CLUE II. Findings do not replicate previous reports of a protective association between lycopene and prostate cancer, but they suggest potential chemopreventive effects of gamma-tocopherol on prostate cancer.

Aged↗
PubMed2003

Effects of maternal antioxidant supplementation on maternal and fetal antioxidant levels: a randomized, double-blind study.

OBJECTIVE: We sought to determine whether vitamins C and E could be delivered to the fetal-placental unit through maternal oral supplementation. STUDY DESIGN: In a randomized, double-blind study, 20 women received a daily prenatal vitamin with or without 400 IU of vitamin E and 500 mg of vitamin C, starting at 35 weeks' gestation. At randomization, a nutritional questionnaire, plasma vitamin C and E and red blood cell (RBC) vitamin E levels were determined. At delivery, concentrations of maternal and fetal plasma vitamin C and E, maternal and fetal RBC vitamin E, amniotic fluid vitamin C, and chorioamnion vitamin E and tensile strength were determined. RESULTS: Maternal plasma vitamin E levels increased in the supplemented women but not in the control subjects. No changes in maternal vitamin C levels were noted. Maternal plasma vitamin C concentrations at delivery correlated closely with amniotic fluid vitamin C levels. Similarly, maternal plasma vitamin E levels at delivery correlated with the chorioamnion concentration of vitamin E. CONCLUSIONS: Maternal plasma vitamin E levels are increased by oral supplementation. Maternal plasma vitamin C and E concentrations correlate with the concentration of vitamin C in the amniotic fluid and vitamin E in the chorioamnion, respectively.

Adult↗
PubMed2003

Smoking and exposure to environmental tobacco smoke decrease some plasma antioxidants and increase gamma-tocopherol in vivo after adjustment for dietary antioxidant intakes.

BACKGROUND: Free radicals in cigarette smoke may cause oxidative damage to macromolecules, contributing to cardiovascular diseases and cancer. Decreased plasma antioxidant concentrations may indicate cigarette smoke-related oxidative stress. OBJECTIVE: We compared the effects on plasma antioxidant concentrations in cotinine-confirmed active and passive smokers with those in nonsmokers, independent of differences in dietary intakes and other covariates. DESIGN: Plasma samples from 83 smokers, 40 passive smokers, and 36 nonsmokers were analyzed for total ascorbic acid, alpha- and gamma-tocopherols, 5 carotenoids, retinol, and cotinine. Groups were compared by using analysis of variance with adjustment for sex, age, race, body mass index, alcohol intake, triacylglycerol concentration, fruit and vegetable intakes, and dietary antioxidants. RESULTS: After adjustment for dietary antioxidant intakes and other covariates, smokers and passive smokers had significantly lower plasma beta-carotene concentrations than did nonsmokers (0.15, 0.17, and 0.24 micro mol/L, respectively) and significantly higher gamma-tocopherol concentrations (7.8, 7.8, and 6.5 micro mol/L, respectively). Smokers had significantly lower plasma ascorbic acid and beta-cryptoxanthin concentrations than did nonsmokers and passive smokers (ascorbic acid: 43.6, 54.5, and 54.6 micro mol/L, respectively; beta-cryptoxanthin: 0.12, 0.16, and 0.16 micro mol/L, respectively) and significantly lower concentrations of lutein and zeaxanthin than did nonsmokers (0.33 compared with 0.41 micro mol/L). The P values for all the differences described above were < 0.05. No significant differences in plasma concentrations of alpha-tocopherol, alpha-carotene, total carotenoids, lycopene, or retinol were observed. CONCLUSIONS: These results indicate that cigarette smokers and nonsmokers exposed to cigarette smoke have a significantly lower plasma antioxidant status than do unexposed nonsmokers, independent of differences in dietary antioxidant intakes. Further research is required to explain why plasma gamma-tocopherol concentrations were significantly higher in smokers and passive smokers than in nonsmokers.

Adult↗
PubMed2003

Vitamin C supplementation decreases oxidative stress biomarker f2-isoprostanes in plasma of nonsmokers exposed to environmental tobacco smoke.

Exposure to environmental tobacco smoke (ETS) has been linked to increased risk of lung cancer and cardiovascular diseases in nonsmokers. Current research suggests that some of these diseases are associated with elevated oxidative stress. We investigated the effect of antioxidant (AO) intervention on the lipid peroxidation biomarker F2-isoprostanes (F2-IsoPs), an index of oxidative stress, in plasma of nonsmokers exposed to ETS (passive smokers). We measured free F2-IsoP concentrations in plasma of 67 passive smokers at baseline and after 2 mo of daily intervention with AOs or placebo. The study subjects (47 females, 20 males; mean age 46 +/-15) were randomized into one of three treatment groups: vitamin C, "mixture" (vitamin C, vitamin E, and a-lipoic-acid), and placebo. Investigated confounders included plasma baseline AO levels, lipid and total cholesterol profiles, transferrin saturation, and C-reactive protein. Plasma F2IsoP concentrations of subjects in the vitamin C and mixture groups decreased significantly by 17.2 pmol/l (P = 0.0105) and 19.2 pmol/l (P = 0.0083) when compared with the placebo group (11.4% and 12.7%, respectively). Daily AO supplementation (especially with vitamin C) decreases this oxidative stress biomarker in passive smokers. This finding might be of importance for the prevention of ETS-associated adverse health effects in nonsmokers.

Adult↗
PubMed2003

Vitamin B12 deficiency. Recognizing subtle symptoms in older adults.

Vitamin B12 deficiency is a common but under-recognized, yet easily treatable disorder in older adults. Although several causes exist, food-cobalamin malabsorption is now believed to be the most common etiology. Complications of vitamin B12 deficiency are myriad, ranging from lethargy and weight loss to dementia. Causes of deficiency include failure to separate vitamin B12 from food protein, inadequate ingestion, absorption, utilization, and storage as well as drug-food interactions leading to malabsorption and metabolic inactivation. The roles of B12 deficiency, elevated homocysteine and elevated methylmalonic acid in various disease states are still evolving. Timely screening and replacement of vitamin B12 will help prevent many complications.

Aged↗