Smoking in pregnancy and vitamin B 12 metabolism

Vitamin B12 reversed anxiety and depression induced by adolescent nicotine withdrawal through alteration the inflammatory, oxidative and serotoninergic profiles in male rats

BACKGROUND

The present study aims to assess the effect of vitamin B12 (Vit B12) on depression-like behavior caused by nicotine (Nic) withdrawal, which is more likely due to the anxiogenic effect of Nic in adolescent male rats, through assessing behavioral and biochemical analysis.

METHODS

Adolescent male rats were divided into vehicle (received normal saline), and experimental groups that received Nic (2 mg/kg, intraperitoneally (i.p.)) for three consecutive weeks and after that, the group that received normal saline was divided into two groups, one of which returned to a regular diet, and the second one received Vit B12 (1.5 mg/kg). The Nic group was divided into five groups, one of which received bupropion (Bup, 20 mg/kg), three of which received different doses of Vit B12 (0.5, 1, and 1.5 mg/kg), and the last one returned to a normal diet without treatment, which was considered as the withdrawal period.

RESULTS

Behavioral analysis showed that Nic withdrawal induced anxiety and depression. Vit B12 and Bup reduced anxiety and depression induced by Nic withdrawal. The biochemical analysis demonstrated the more activity of oxidative stress factors and pro-inflammatory cytokines in which Nic was administered, whereas both Vit B12 and Bup reversed the results and improved the activity of both antioxidant and anti-inflammatory parameters. Furthermore, both serum and cortical Vit B12 levels dramatically decreased in nicotine group, whereas treatment with both Vit B12 and Bup as desirable treatments corrected Vit B12 levels.

CONCLUSION

According to the present findings, the results revealed that Vit B12 is comparable with Bup in attenuation of Nic withdrawal symptoms. In addition, both Bup and Vit B12 improved the decreased serum and cortical levels of Vit B12, which caused by nicotine. Administration of Vit B12 in normal animals demonstrated better results in reducing antioxidant and anti-inflammatory parameters, which explores new hope to introduce Vit B12 as a novel antioxidant and anti-inflammatory agent to treat not only withdrawal, but also other diseases related to the prominent role of oxidative stress or inflammatory pathways, such as Alzheimer's disease.

Evaluation of the Relationship Between Smoking and Insulin Resistance: A Case-Control Study

Introduction: In recent years, there has been a surge in research focusing on the link between smoking and insulin resistance in the context of obesity and diabetes. In this study, our objective was to investigate the relationship between smoking and insulin resistance.

Materials and Methods: This is a case-control study. The case and control groups were formed using the hospital patient information database and clinically randomized using data obtained, including age, gender, height, and weight. The case group for this study consisted of smokers, whereas the control group consisted of non-smokers. Chi-square tests were used to compare numbers and rates, and independent sample t-tests were used for the averages. Binary logistic regression analysis was performed between the case and control groups.

Results: According to logistic regression analysis, the odds ratio for non-smokers was 0.59 (0.31-1.14). The risk of insulin resistance is decreased by 41% non-significantly in non-smokers. The odds ratio for age was 1.03 (1.01-1.05). When the age variable increases by one unit, the risk of insulin resistance increase by 1.03 times.

Conclusion: Our study found no significant relationship between smoking and insulin resistance in healthy individuals. The relationship between smoking and insulin resistance, as reported in the scientific literature, may be suggestive of an association in which smoking exacerbates insulin resistance as a result of other contributing factors rather than serving as a direct causal factor. Further studies are warranted to elucidate the potential mechanisms underlying this association fully.

Prevalence of vitamin B-12 insufficiency during pregnancy and its effect on offspring birth weight: a systematic review and meta-analysis

BACKGROUND

Vitamin B-12 and folate are micronutrients essential for normal embryogenesis. Vitamin B-12 insufficiency in pregnancy is high in certain parts of the world, such as India, and although this has been linked to low birth weight (LBW) in these populations, the relation between vitamin B-12 and birth weight (BW) elsewhere is unknown.

OBJECTIVES

We performed a systematic review to assess 1) the worldwide prevalence of vitamin B-12 insufficiency in pregnancy and 2) its association with BW.

DESIGN

A search of 5 electronic databases was performed to identify eligible articles. Random-effects meta-analysis was conducted according to geographic regions and pregnancy trimesters for the prevalence subreview and by categorical measures of BW.

RESULTS

A total of 57 and 23 articles were included for the prevalence and BW subreviews, respectively. The pooled estimates of vitamin B-12 insufficiency were 21%, 19%, and 29% in the first, second, and third trimesters, respectively, with high rates for the Indian subcontinent and the Eastern Mediterranean. The large heterogeneity between studies was partially addressed by creating a standardized score for each study (mean vitamin B-12 insufficiency ÷ cutoff value), which internally corrected for geographic region, trimester, and assay type. Twelve of the 13 longitudinal studies included showed a decrease in mean or median vitamin B-12 across trimesters. Pooled analysis showed nonsignificantly lower maternal vitamin B-12 concentrations in LBW than in normal-BW infants and higher odds of LBW with lower vitamin B-12 values (adjusted OR: 1.70; 95% CI: 1.16, 2.50), but studies from India largely contributed to the latter.

CONCLUSIONS

Our review indicates that vitamin B-12 insufficiency during pregnancy is common even in nonvegetarian populations and that concentrations of vitamin B-12 decrease from the first to the third trimester. There is no consistent association between vitamin B-12 insufficiency and LBW. However, given the long-term risks of LBW, this observation warrants further cohort studies and randomized controlled trials.

Monitoring micronutrients in cigarette smokers

Smoking is associated with oxidative stress and increased risks of many chronic diseases that both shorten life and impair its quality. Low concentrations of several micronutrients, especially the antioxidants vitamin C and beta-carotene, are also associated with smoking, and there has been much interest in determining whether deficiencies in micronutrients are involved etiologically in smoking-related diseases. The objective of this review was to bring together reports on dietary intakes, biochemical indicators of micronutrient status, and results of some intervention studies on micronutrients where authors had compared outcomes in smokers and non-smokers. The micronutrients discussed are vitamins A, E, and C; the carotenoids; some of the B-vitamin group; and the minerals selenium, zinc, copper, and iron. The data were then examined to determine whether effects on the biochemical markers of micronutrient status were due to differences in dietary intakes between smokers and non-smokers or to the consequences of inflammatory changes caused by the oxidative stress of smoking. It was concluded that although smoking is associated with reduced dietary intake of vitamin C and carotenoid-containing foods, inflammatory changes increase turnover of these micronutrients so that blood concentrations are still lower in smokers than non-smokers even when there is control for dietary differences. In the case of vitamin E, there is some evidence for increased turnover of this nutrient in smokers, but this has little to no influence on blood concentrations, and there are no differences in dietary intake of vitamin E between smokers and non-smokers. Serum concentrations of vitamin A, folate, and vitamin B12 and B6 markers do not appear to be influenced by smoking, although there is some influence of dietary intake on concentrations of these nutrients in the body. In the case of the minerals examined, the main effects on biochemical markers of mineral status were attributed to inflammation and were therefore greater in heavy or long-term smokers. Serum concentrations of selenium and erythrocyte GPx activity were lower in smokers. Erythrocyte CuZn-SOD activity and serum ceruloplasmin concentrations were elevated, while serum zinc concentrations were depressed only in heavy smokers. Lastly, smoking appears to affect iron homeostasis mainly by changing hemoglobin concentrations, which were in general increased. Serum iron, TfR, and ferritin were mostly unaffected by smoking, except in pregnancy where there is evidence of increased erythropoiesis causing lower saturation of plasma transferrin and some evidence of lowering of iron stores.

Folic acid, Vitamin B(12), and homocysteine in smoking and non-smoking pregnant women

INTRODUCTION

Lower plasma levels of vitamins may result in hyperhomocysteinemia, a known risk factor in pregnancy. As smoking may alter nutrition, we were interested in its effect on folate and Vitamin B(12) in pregnancy.

MATERIALS AND METHODS

A cross-sectional study of 62 smoking and 76 non-smoking healthy pregnant women. Serum folic acid, Vitamin B(12) and homocysteine were measured at four points in pregnancy: 0-10, 11-20, 21-30 and 31-40 weeks.

RESULTS

Folate concentrations of the smoking women decreased continuously during pregnancy, and were significantly lower than those of non-smoking women during the last 30 weeks. Vitamin B(12) levels decreased significantly in both groups. The homocysteine levels were higher in the smoking group during the second-half of pregnancy.

DISCUSSION

Smoking women have lower and decreasing folate levels during pregnancy, possibly as a result of lower intake of these nutrients. Lower folate levels can lead to hyperhomocysteinemia, a known risk factor for several complications in pregnancy. This is an other important reason to convince pregnant women to refrain from smoking.

Determinants of cobalamin status in newborns

OBJECTIVE

Cobalamin deficiency accompanied by bone marrow dysfunction and impaired central nervous system development has been reported in infants who were born to mothers with low cobalamin intake. We investigated the relation between cobalamin status in newborns and in their healthy mothers who consumed an omnivorous diet.

METHODS

Serum cobalamin and the functional markers plasma methylmalonic acid (MMA) and total homocysteine (tHcy) were determined in 173 newborns and their mothers. Forty-five children and mothers were reinvestigated after 6 weeks.

RESULTS

At birth, median (interquartile range) serum cobalamin levels were 245 (175-323) pmol/L in the mothers and 314 (238-468) pmol/L in the newborns. In the neonates, serum cobalamin, but not folate, was inversely associated with MMA and tHcy. Among maternal factors, low serum cobalamin was the strongest predictor of impaired cobalamin function (defined as low cobalamin, high tHcy, or high MMA levels) in the newborns. After 6 weeks, the maternal cobalamin levels had increased (to 421 [271-502] pmol/L), whereas the newborn levels had declined (to 230 [158-287] pmol/L). In the same interval, the infants had a marked increase in plasma MMA (from 0.29 [0.24-0.38] to 0.81 [0.37-1.68] micromol/L). At 6 weeks, parity was a strong predictor of cobalamin status in the infant.

CONCLUSION

The cobalamin status in the neonatal period is strongly associated with maternal cobalamin status and parity. A reduction in serum cobalamin and an increase in metabolite levels are consistent with impaired cobalamin function in a significant portion of the infants who were born to healthy, nonvegetarian mothers.

Vitamin B12 among parturients and their newborns and its relationship with birthweight

Vitamin B12 (Cobalamin) is an essential nutrient in the diet of humans, particularly during pregnancy, nevertheless very few epidemiological studies have been reported, particularly concerning variation factors. The purpose of this study is to assess the role of vitamin B12 on birthweight after taking into account potential confounders, such as obstetrical, socioeconomic, and biological factors which will be identified. This study was conducted on 188 single births occurring during a 5-month period in an obstetrical care unit in Paris. Vitamin B12 plasma levels and folate plasma levels of mothers and cords along with haematological parameters were measured. Social and obstetrical features of the mothers as well as their tobacco exposure and alcohol consumption were recorded. Cord blood vitamin B12 levels were highly correlated with maternal levels (r = 0.63, P less than 0.001) and were 2-3-fold higher. Three variation factors of vitamin B12 were identified: maternal age, ethnicity and tobacco exposure. Negative correlations between birthweight and vitamin B12 levels were observed only among the smoker group (r mothers = -0.46, P less than 0.05 and r cords = -0.42, P less than 0.05). After adjustment for ethnicity and parity, birthweight remained negatively linked to vitamin B12 in smokers. This relationship could suggest that the availability of vitamin B12 for fetal development depends on certain biological factors present only in mothers who smoked. We hypothesized this relationship could be explained, in part, by lipid metabolism, particular to smokers.

Smoking during pregnancy: prevalence, effects, and intervention strategies

Smoking prevalence rates have been declining in the United States, but an estimated 25 percent of pregnant women continue to smoke. Smoking during pregnancy is considered one of the leading, preventable causes of low birthweight. Research attributes 21 to 39 percent of low birthweight to smoking during pregnancy, although the exact mechanism of the effect is not completely understood. Several well-designed studies have shown that pregnant smokers are more likely to stop smoking if they are provided with systematic interventions. This overview describes adverse consequences, prevalence, possible mechanisms of action, and prenatal smoking-cessation programs that have proved effective. A five-step approach is outlined for clinicians who want to counsel their prenatal clients.

Growth of children from 0-5 years: with special reference to mother's smoking in pregnancy

A cohort of 1163 pregnant women in two small towns in South Wales, UK, was identified and followed until the children born to them were five years of age. Growth in these children is described and a number of determinants identified. Social-class differences were very small at birth but differences in height became clear by the age of two years and in head circumference before this. In height the differences were largely accounted for by greater growth in social class I, but there was a gradient in head circumference throughout all the social classes. The social class effects gradually increased as the children became older. Parity of the mothers had a small effect on size at birth but age of the mother had no effect once parity was allowed for. Data on illnesses in the children were collected but no effect on growth could be detected. By far the most important determinant of growth which could be controlled is maternal smoking. About 40% of the women smoked, about 17% heavily (15 or more cigarettes per day) and the prevalence of smoking altered little during pregnancy. There was a graded effect of smoking on growth up to a 9% deficit in birth-weight, a 2% deficit in length at birth and a 1.5% deficit in head circumference in the babies born to the mothers who smoked most heavily (25 or more cigarettes per day) compared with non-smokers. There effects decreased with age but there were still residual effects at age five years.

Sodium nitroprusside, pregnancy and multiple intracranial aneurysms

Pregnancy should not greatly alter the anaesthetic management of a patient with intracranial aneurysms. Controlled hypotension is the method of choice for meeting surgical requirements. Primary attention to the mother with judicious use of sodium nitroprusside is unlikely to compromise the foetus. Sodium nitroprusside is not teratogenic in animal experiments. At present, the biochemical consequences for the foetus of prolonged nitrous oxide anaesthesia are not clear. Present data would support folinic acid administration.

Smoking and pregnancy

Smoking during pregnancy is associated with many adverse outcomes, including fetal and neonatal death. These consequences are tragic in many ways, but perhaps the greatest tragedy is that they are preventable if the smoker ceases to smoke during pregnancy. Although in some instances the so-called constitutional hypothesis is difficult to disprove, the available evidence seems more than convincing that it is smoking itself, and not the smoker's unique constitution, that is responsible. Cessation from smoking is clearly advisable at any time, but more so during pregnancy when every cigarette affects both the smoker and her unborn child.

Maternal passive smoking and fetal serum thiocyanate levels

Passive smoking, exposure of the nonsmoker to air contaminated with tobacco smoke, has been reported to have several adverse consequences for health. However, its effects on the fetus are unknown. Detailed smoking histories and fetal SCN (thiocyanate) levels were obtained in 107 low-risk pregnancies in order to evaluate fetal exposure to this metabolic byproduct of tobacco smoke. Among nonsmokers, fetal SCN levels were increased in association with passive smoking in the home (p less than 0.05). Significant differences in clinical characteristics were associated with passive smoking, but none of these differences were accounted for a significant increase in fetal SCN levels. These findings suggest that maternal passive smoking exposes the fetus to SCN, which is reported to be an effective biochemical marker of overall exposure to smoking, and which is known to be toxic in higher doses.

Thiocyanate and drinking during pregnancy

Alcohol appears to have a relatively direct effect in decreasing fetal growth; however, it also appears that other factors associated with alcohol consumption may also contribute to lowered birthweight. Three studies have suggested that beverage source of alcohol may be a determinant of decreased intrauterine growth and that beer may have a comparatively greater effect than wine and liquor. Since beer is reported to contain thiocyanate (SCN), a substance which has been implicated as a determinant of fetal growth retardation in relation to cigarette smoking, we studied maternal and fetal serum SCN levels in 82 pregnancies. After controlling for maternal characteristics, gestational age, and tobacco and marijuana use, the quantity of beer consumed was found to have a significant positive correlation with fetal serum SCN (p less than 0.005). Consumption of other types of alcoholic beverages was not significantly associated with elevated fetal serum SCN, although the numbers of wine and liquor drinkers in this study were limited. Further research is warranted to explore the possibility that the correlation of beer consumption with increased SCN might provide at least one explanation for the reported linkage of diminished fetal growth and beer drinking.

Effects of cigarette smoking on maternal nutrition and the fetus

Available evidence supports the importance of including facts about smoking and pregnancy in all teaching to women in the childbearing years. The incidence of low birthweight infants is possibly almost twice as high among smoking mothers, and these low birthweight babies are known to be at risk on several counts. Compromised utilization of vitamins and minerals is presented as a causative factor: calcium, vitamin B12, and vitamin C levels are lower in smokers. Other vitamin levels may be affected. Poor nutrition and other factors connected with smoking may result also in stillbirths, spontaneous abortions, congenital anomalies, and cancer in the offspring. Nurses have a unique opportunity to contribute to maternal-child health by teaching and counseling about smoking in pregnancy.

[Smoking during pregnancy: educational aspects of a behavioral problem]

Descreve-se o hábito de fumar de mulheres internadas no Serviço de Obstetrícia de um hospital do município de São Paulo, Brasil, assim como conhecimentos a respeito dos efeitos do fumo durante a gestação e orientação recebida durante esse período. Apresentam-se algumas implicações para a educação em saúde, considerando-se diferentes níveis de programas anti-fumo.

Subacute combined degeneration of the spinal cord and the vitamin B12 metabolism, a clinical study

In 28 patients suffering from subacute combined degeneration of the spinal cord, vitamin B12 metabolism was investigated. Two postulates, proving vitamin B12 deficiency and excluding another cause for the clinical symptoms, have to be fulfilled. Two patients had no disturbance in their vitamin B12 metabolism. Seven patients had a distinct vitamin B12 deficiency. In the remaining 19 patients we found a mild vitamin B12 deficiency. Of these patients, 5 had had a subtotal gastrectomy, one had had a low absorption of vitamin B12, and 13 patients we could not find a distinct cause for the vitamin B12 deficiency. It is not impossible that nutritional habits can be hold responsible for this deficiency. The question whether these 13 patients should be treated with vitamin B12 for the rest of their lives is difficult to answer. It is a conditio sine qua non that in the patients with S.C.D. the vitamin B12 metabolism is examined circumstantially. By so doing, it may be possible to detect, in cases with minor clinical signs and symptoms of S.C.D., the cause of their illness.

Smoking in pregnancy--effects on birth weight and on cyanide and thiocyanate levels in mother and baby

A total of 45 expectant mothers (20 smokers and 25 non-smokers) and their babies was studied and, after 14 smokers and 14 non-smokers had been closely matched for age, height, parity and social class, significant differences were observed between smokers and non-smokers in the birth weights of the babies and in cyanide and thiocyanate levels in maternal blood and urine.

Cigarette smoking in pregnancy: Associations with maternal weight gain and fetal growth

1159 mother-infant "pairs" have been studied to examine the inter-relationship of cigarette smoking in the latter half of pregnancy, maternal weight gain, and fetal growth. Non-smokers gained significantly more weight than heavy smokers (greater than 15 cigarettes per day) while light-to-moderate smokers (1-14 cigarettes a day) were intermediate. Birth-weight, length, and head circumference of the infants showed a similar gradient with infants born to non-smokers being heavier, longer, and with larger head circumferences than those born to heavy smokers. Co-variance analysis showed that a large part of the effect of maternal smoking is mediated through maternal weight gain with only a very small additional direct effect on the fetus. This suggests that increasing weight gain in smoking mothers might prevent some of the harmful effects of smoking on fetal growth. A randomised controlled trial of diet supplementation of smoking mothers would seem justified.