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Biomedical subjects

P Nestel

Publications and source records attributed to P Nestel.

At least 19 recordsLinked to original sources
PubMed2001

Effects of fish oils and fish on cardiovascular disease.

The effects of fish oils, fish, and omega-3 (n-3) fatty acids on cardiovascular functions and outcomes in recently published studies are reviewed. The original hypothesis that eating fish is protective has been largely sustained but refined to indicate benefit mainly in those who are at increased risk. Biologic plausibility has been extended from the established benefit of lipid-lowering to improvements in vascular and arterial functions. A major intervention trial in patients with cardiovascular disease has confirmed the benefits of moderate amounts of long-chain n-3 fatty acids. Thus, the triad of evidence comprising epidemiology, biologic plausibility, and interventional success through a randomized, controlled trial has been established.

Animals↗
PubMed2001

Simvastatin improves arterial compliance in the lower limb but not in the aorta.

UNLABELLED: Several cardiovascular risk factors adversely affect arterial compliance or the distensibility of large arteries. The role of raised low-density lipoproteins (LDL) cholesterol is uncertain, most studies having shown little effect. We, therefore, investigated whether lowering LDL would improve arterial compliance. Twenty hypercholesterolemic subjects (LDL cholesterol 4.95+/-1.11 mmol/l) were randomized to simvastatin (20 or 40 mg daily) or placebo, each for 4 weeks. Arterial function was assessed at the end of the placebo and simvastatin periods, systemic arterial compliance (SAC) and pulse wave velocities (PWV) centrally (aorto-femoral) and peripherally (femoral-posterior tibial). RESULTS: Lipoproteins (LDL) cholesterol was reduced similarly with 20 and 40 mg simvastatin (ten subjects each dose) and data were pooled. Lipoproteins (LDL) cholesterol fell 39%, plasma triglyceride fell 18% and high-density lipoprotein (HDL) cholesterol rose 12%, all significant. Systemic arterial compliance (SAC) and central PWV did not change significantly but peripheral PWV showed evidence of greater compliance after simvastatin (10.1+/-1.3 vs. 9.4+/-1.3 m/s with placebo and simvastatin, P<0.03), distensibility being inversely related to PWV. Improvement in PWV was greatest in those with poorest baseline values, r=0.50; P<0.02. CONCLUSION: Peripheral PWV was alone improved with LDL lowering probably because of the muscularity of that arterial bed; central PWV and SAC (in the elastic aorta) were not influenced.

Anticholesteremic Agents↗
PubMed2000

The effects of dietary supplementation with isoflavones from red clover on the lipoprotein profiles of post menopausal women with mild to moderate hypercholesterolaemia.

The effects of dietary isoflavone supplementation using a purified extract of red clover containing approximately biochanin A 26 mg, formononetin 16 mg, daidzein 0.5 mg and genistein 1 mg per tablet at doses of one or two tablets per day were compared to placebo in a three-period, randomised, double blind, ascending dose study in 66 post menopausal women with plasma cholesterol levels between 5.0 and 9.0 mmol/l. Each treatment period lasted 4 weeks and a further nine women received placebo for the full 12-week period. All women consumed a low isoflavone diet for 2 weeks preceding the commencement of the study and for the 12-week study period. Urinary isoflavone excretion was very low in subjects receiving placebo but increased in a dose-dependent manner during therapy with one and two of isoflavone tablets. Dietary supplementation with isoflavones did not significantly alter total plasma cholesterol, LDL cholesterol, HDL cholesterol or plasma triglyceride levels. However, inverse correlations were found between urinary genistein excretion and plasma triglyceride levels and between urinary O-DMA excretion (an isoflavone metabolite) and plasma triglyceride levels in subjects receiving one isoflavone tablet, suggesting a weak relationship between isoflavone intake and plasma triglycerides which may be influenced by individual differences in isoflavone absorption or metabolism. The results suggest that isoflavone phytoestrogens from red clover in the proportions and quantities studied do not significantly alter plasma lipids in post menopausal women with moderately elevated plasma cholesterol levels.

Aged↗
PubMed2000

Undernutrition in relation to childhood infections: a prospective study in the Sudan.

OBJECTIVE: The aim of the study was to examine the relationships between nutritional status and diarrhoea and respiratory infections. DESIGN: Prospective cohort study within the framework of a randomized double-blind placebo-controlled intervention trial. SETTING: In rural communities in the Khartoum and Gezira regions, in Northern Sudan. SUBJECTS: 28,753 Sudanese pre-school children between 6 months and 6 y old. METHODS: Relative risks of subsequent diarrhoea and respiratory infections in relation to nutritional status measured by anthropometry (Z-scores of height-for-age (H/A), weight-for-height (W/H), and weight-for-age (W/A), which reflect stunting, wasting and underweight, respectively) were estimated using odds ratios from logistic regression adjusting for various covariates. RESULTS: H/A, W/H and W/A were significantly and inversely associated with subsequent diarrhoea and febrile diarrhoea (P for trend <0.001) with risks being 2.00 times higher (95% confidence interval, CI (1.64, 2.43)) among children with W/A Z-scores below -4 Z, and 1.75 times higher (95% CI (1.56, 1.96)) among those with a W/A Z-score between -4 and -3 Z compared with children having a W/A Z-score > or =1. Age, gender, region of residence and seasonality modified these associations. Also, febrile cough was inversely associated with W/A and W/H (P<0.03), with risks ranging from 1.41 times higher (95% CI (1.02, 1.97)) to 1.21 times higher (95% CI (1.04, 1.41)) in the group of underweight children with W/A Z-scores below -4 and between -2 and -1 Z, all compared with normally nourished children (> or =-1 Z). CONCLUSIONS: The reduction of severe but also mild and moderate undernutrition is necessary through nutrition, health and socio-economic improvement in order to prevent morbidity.

Body Weight↗
PubMed2000

Effect of weight reduction on the distribution of apolipoprotein A-I in high-density lipoprotein subfractions in obese non-insulin-dependent diabetic subjects.

High-density lipoprotein (HDL) plays an important role in the process of reverse cholesterol transport, which may become suboptimal with increasing body fatness. HDL cholesterol that is reduced in obese subjects paradoxically decreases during weight reduction. To determine how weight reduction affects HDL subclasses that are involved in reverse cholesterol transport, we studied HDL from obese diabetic subjects before and after energy restriction within background diets high in either carbohydrate or monounsaturated fatty acids (MUFAs). Body weight, blood glucose, total cholesterol, and LDL cholesterol decreased after 8 and 12 weeks of weight reduction. With the very-low-fat diet, HDL cholesterol decreased significantly at 8 weeks, but recovered to initial levels after 12 weeks as body weight began to stabilize. Plasma apolipoprotein A-I (apo A-I) decreased substantially and significantly at 8 and 12 weeks with both diets, and was reflected in the reduction of apo A-I in HDL subclasses alpha1, alpha2, pre-beta1, and pre-beta2 + pre-beta3. The calculation of the percentage distribution of apo A-I among HDL species showed that only the proportion of pre-beta1-HDL decreased, whereas alpha2-HDL increased. This led to a significant increase in the alpha1 + alpha2/pre-beta ratio, ie, the ratio of the large cholesterol "storage" or "sink" HDL to the HDL "shuttle" fraction considered to be the initial acceptor of cell cholesterol. These data suggest that despite the reduction in HDL cholesterol and apo A-I, the redistribution of apo A-I in pre-beta1-HDL and alpha-HDL observed with weight reduction appears to revert to the pattern that we have previously reported in lean as opposed to overweight subjects.

Apolipoprotein A-I↗
PubMed2000

Undernutrition and childhood infections: a prospective study of childhood infections in relation to growth in the Sudan.

UNLABELLED: The relationships between both diarrhoea and respiratory infections and linear and ponderal growth were prospectively examined among 28 753 Sudanese pre-school children. Childhood infections were significantly and inversely associated with attained height and attained weight and gain in height and weight over a 6-mo period. They were significantly and positively associated also with stunting after adjusting for age, gender, socio-economic status, dietary variables and previous morbidity. Attained height was on average 17 mm lower (95% CI [-19 -15]) for children with diarrhoea and 11 mm lower (95% CI [-3 -9]) for children with complicated cough than for those without these symptoms. The association between morbidity and attained weight was significant for diarrhoea and complicated cough, but the differences between children with and without symptoms were negligible. The risk of being stunted 6 mo later was 1.38 times (95% CI [1.20 1.59]), 1.29 times (95% CI [0.97 1.72]) and 1.32 times (95% CI [1.13 1.54]) greater among normally-nourished children with diarrhoea, febrile diarrhoea and fever, respectively, than among children without these symptoms. The difference in attained height between children with diarrhoea or complicated cough and those without symptoms increased with age, and was larger among the non-breastfed children compared with breastfed children. CONCLUSION: The results underline the need to reduce child morbidity to prevent the impairment of growth and development.

Child↗
PubMed2000

Dietary vitamin A intake and nondietary factors are associated with reversal of stunting in children.

We examined prospectively the associations between dietary vitamin A intake, nondietary factors and growth in 8174 Sudanese children ages 6-72 mo who were stunted at the start of follow-up. All subjects were weighed and measured at baseline and at 6-mo intervals for 18 mo of follow-up. Dietary vitamin A intake during the prior 24 h was assessed using recall of vitamin A-containing foods at baseline and 6-mo intervals. We examined the association of dietary vitamin A intake with growth and the incidence of recovery of stunting after controlling for age, sex, breast-feeding status and socioeconomic variables. We found that carotenoid intake was associated with a greater incidence of reversal of stunting. Children in the highest quintile grew 13 mm more during the study period than children in the lowest quintile [95% confidence interval (CI): 0-25 mm] in multivariate analyses. The relative risk (RR) of recovery associated with vitamin A intake was greater in infants up to 1 y old (RR = 3.3, CI: 0.9-11.7) than in children > or =3 y of age (RR = 1.0, CI: 0.8-1. 3) (P:-value for interaction = 0.08). Diets rich in carotenoids may increase the rate of recovery from stunting in children. Dietary effects on growth might be strongest among very young children and those who have been most malnourished. Age, sex, breast-feeding status, socioeconomic status and severity of baseline stunting also were associated with reversal of stunting in this population.

Analysis of Variance↗
PubMed2000

Tomato intake in relation to mortality and morbidity among Sudanese children.

The intake of foods that contain high levels of antioxidants may counteract the adverse effects of oxidative stress and lead to improved immune function and reduced risk of infectious disease. We prospectively examined the relationship between the consumption of tomatoes, a rich source of antioxidants, and mortality and diarrheal and respiratory morbidity rates among 28,753 children who were 6-60 mo old and enrolled in a longitudinal study in the Sudan. Children in each household were visited every 6 mo for a maximum of four visits. At each round, mothers recalled whether a child had consumed tomatoes in the previous 24 h. Events (death or morbidity) reported at each round were prospectively allocated according to the number of days of tomato intake. Intake of tomatoes for 2 or 3 d compared with none was associated, respectively, with 48% (relative risk, 0. 53; 95% confidence interval, 0.30-0.91) and 83% (0.17; 0.04-0.72) reductions in morality rates (P: for trend = 0.002). The association between tomato use and death remained statistically significant (P: for trend = 0.004), even after further adjustment for total vitamin A intake. Tomato intake was also associated with a reduced risk of death associated with diarrhea in the week preceding death (P: for trend = 0.009) or fever (P: for trend = 0.04). Intake of tomatoes was also inversely and significantly associated with the risks of diarrheal and respiratory infections. Our data suggest that tomatoes may be beneficial for child health but also emphasize the general importance of food-based approaches to the prevention of micronutrient malnutrition and protection of the health of children in developing countries.

Antioxidants↗
PubMed2000

Introduction

Explore the source record for details and available documents.

Journal Article↗
PubMed1999

Vitamin E improves arterial compliance in middle-aged men and women.

UNLABELLED: Diminished arterial compliance, or loss of elasticity in large arteries, is an emerging cardiovascular risk factor with a reversible component that includes improved endothelial function. Vitamin E, which may reduce cardiovascular risk, can lower vascular resistance. Twenty-eight middle-aged men and women were randomized through a double-blind design to 8 weeks of supplemental vitamin E (400 IU daily) or placebo. Compliance was determined non-invasively from simultaneous measurements of aortic flow and carotid pressure at baseline and after 4 and 8 weeks. RESULTS: arterial compliance increased by 37% at 4 weeks and by 44% at 8 weeks (P = 0.01) only in the vitamin E group and was independent of an effect on arterial pressure. A rise was seen in 12/14 subjects. There was no significant change with placebo (+ 8%). CONCLUSIONS: short-term vitamin E supplementation improves arterial compliance.

Adult↗
PubMed1999

Nutrition of Honduran mothers/caretakers.

In 1996, the Honduran Ministry of Health conducted a national micronutrient survey of children 12-71 months old, which also included an assessment of the nutrition status of their mothers/caretakers. The 1,126 mothers/caretakers who participated in the survey tended to be short and plump. About 15% of them were at obstetric risk by virtue of their short stature and/or low body weight. About 9% had chronic energy deficiency (CED), but 27% were at least 20% overweight. CED was associated with socioeconomic indicators of poverty. Risk factors for being at least 20% overweight included being over 30 years old, not breast-feeding, having attended no higher than grade 4, 5, or 6 of primary school, coming from a wealthier household, and living in San Pedro Sula or medium-sized cities. Among the women surveyed, 26% of nonpregnant and 32% of pregnant mothers/caretakers were anemic. The likely principal cause of anemia was the low intake of bioavailable iron from food and, in some cases, excessive iron loss associated with intestinal parasites, especially hookworm. Only 50% of the mothers/caretakers participating in this study had received iron during their last pregnancy, and just 13% had received postpartum vitamin A. The results highlight the need to develop and implement an effective program to control iron deficiency anemia in women of reproductive age, including by fortifying such widely consumed foods as processed wheat and maize flour and by routinely administering iron supplements to high-risk groups. Postpartum vitamin A supplementation should be encouraged to protect both the mother and newborn infant against vitamin A deficiency.

Adult↗
PubMed1999

Vitamin A deficiency and anemia among children 12-71 months old in Honduras.

Vitamin A deficiency (VAD) and iron deficiency anemia (IDA) have been recognized as public health problems in Honduras for over 30 years. This paper, based on the 1996 National Micronutrient Survey on 1678 children 12-71 months of age, presents the results for vitamin A status and anemia prevalence, as well as the level of vitamin A in sugar at the household level. The results showed that 14% of the children were subclinically vitamin A deficient (plasma retinol < 20 micrograms/dL) and 32% were at risk of VAD (plasma retinol 20-30 micrograms/dL). These data indicate that VAD is a moderate public health problem in Honduras. Logistic regression analysis showed that children 12-23 months old living in areas other than the rural south of the country were at greatest risk of subclinical VAD. Infection, indicated by an elevated alpha-1-acid-glycoprotein level, increased the risk of subclinical VAD more than three-fold. Children from households that obtained water from a river, stream, or lake were at twice the risk of subclinical VAD compared with other children. That same doubled risk was found for children from a household with an outside toilet. VAD can be controlled by fortifying sugar. Retinol levels in sugar at the household level were about 50% of those mandated by Honduran law. There appears to be significant leakage of unfortified sugar into the market. This is particularly true in the rural north, where 33% of samples contained no retinol. Overall, 30% of children were anemic (Hb < 11 g/dL). Logistic regression analysis showed that children whose fathers lived with them but who had not attended at least grade 4 of primary school were at 33% greater risk of being anemic. Infection and being underweight increased the risk of being anemic by 51% and 21%, respectively. Many of the anemic children had not been given iron supplements, suggesting health care providers may not be aware that anemia is widespread among young children and/or know how to diagnose it.

Age Factors↗
PubMed1999

Undernutrition among Honduran children 12-71 months old.

In 1996, the Ministry of Health of Honduras conducted a national micronutrient survey that included anthropometric measurements to determine the nutrition status of children 12-71 months old. Among the 1,744 children who participated, 38% of them were stunted, including 14% who were severely stunted; 24% were underweight, of which 4% were severely underweight; and 1% were wasted, of which 0.1% were severely wasted. The country can be divided into three groupings based on the level of stunting and underweight: 1) lowest prevalence: Tegucigalpa, San Pedro Sula, and medium cities; 2) medium prevalence: other urban areas, the rural north, and the rural south; and 3) highest prevalence: the rural west. Using logistic regression analysis, the important determinants of stunting were found to be: mother/caretaker's and father's schooling, source of water, the dominion (geographic location and strata) in which the child lived, and the "possession score" for ownership of such items as a radio, television, refrigerator, stereo system, and electric iron. The predictors for underweight were micronutrient status, diarrhea, maternal/caretaker's schooling, type of toilet, and possession score. Historical data indicate that the national prevalence of chronic undernutrition has changed little over the last 10 years despite the number of national food and nutrition plans implemented and the significant improvements in health services. It is possible that these positive interventions have been offset by the slow progress in economic development. Future nutrition interventions should take into account household-level perceived needs and priorities in order to set realistic nutrition targets.

Age Factors↗
PubMed1999

Effects of insulin therapy and glycemic control on distribution of HDL alpha and pre-beta subfractions in non insulin-dependent diabetic subjects.

BACKGROUND AND AIM: The heterogeneous population of HDL particles can be separated into six classes which may provide a more sensitive index of cardiovascular risk than HDL cholesterol. The aim of this study was therefore to evaluate HDL distribution in NIDDM. METHODS AND RESULTS: Twenty-five individuals were treated with diet and sulfonylurea and 14 with insulin; both groups had similar plasma lipid profiles and BMI, but the insulin-treated subjects were older and their diabetes was of longer duration. The major findings were a greater proportion of apoA1 in alpha 1-HDL in the insulin-treated group (24.3 +/- 5.2% vs 20.8 +/- 4.0%), which is a desirable profile, and a greater proportion of pre-beta 1-HDL, which are the initial acceptors of cellular cholesterol. CONCLUSIONS: Our results suggest a beneficial influence of insulin treatment on reverse cholesterol transport. Moreover, glycemic control (HbA1c) also related to alpha 3-HDL significantly (r = 0.51; p < 0.01), indicating an association between poorer glycemic control and an adverse HDL profile.

Administration, Oral↗
PubMed1999

The role of provitamin A carotenoids in the prevention and control of vitamin A deficiency.

That beta-carotene is the main source of vitamin A in fruits and vegetables has been known for many years. Many studies have been conducted to assess bioconversion of beta-carotene to vitamin A in animals. More recently, bioconversion studies using stable-isotopically labeled beta-carotene have been used to assess bioconversion in humans. The efficiency of the bioconversion of beta-carotene to vitamin A has been accepted to be six but this value may vary depending on vitamin A status and the amount of beta-carotene consumed. This paper reviews the human studies on purified beta-carotene supplements and/or consumption of fruits and vegetables conducted to ascertain whether beta-carotene can alter the vitamin A status of deficient populations. The conclusion is that data are lacking from well-designed studies to show that, with the possible exception of red palm oil, beta-carotene-rich foods are as effective as vitamin A supplements for eliminating vitamin A deficiency. Nevertheless, the data do show that beta-carotene-rich foods may be important for preventing vitamin A deficiency.

Carotenoids↗
PubMed1998

Vitamin E reduces cholesterol esterification and uptake of acetylated low density lipoprotein in macrophages.

The effects of vitamin E on cholesteryl ester (CE) metabolism in J774 cells were examined. Pretreatment of J774 cells with vitamin E at concentrations above 50 microM significantly decreased acetylated low density lipoprotein (LDL)-induced incorporation of [14C]oleate into CE in cells in a dose-dependent manner. This was partly due to vitamin E also significantly inhibiting the uptake of [3H]CE-labeled acetylated LDL by J774 cells. A trend existed toward suppression of acyl-CoA:cholesterol acyltransferase (ACAT) activity in the cell lysate at high vitamin E concentration, but there was no effect on hydrolysis of CE. These data indicate that vitamin E reduces the uptake of modified LDL and suppresses ACAT activity, resulting in less cholesterol esterification in macrophages: a novel mechanism underlying the antiatherogenic properties of vitamin E.

Animals↗
PubMed1998

A longitudinal study of prolonged breastfeeding in relation to child undernutrition.

BACKGROUND: In a number of studies prolonged breastfeeding was associated with a higher risk of undernutrition, although most of these studies are limited by their cross-sectional design which does not allow examination of temporal relationships between full weaning and undernutrition. METHODS: The relationship between prolonged breastfeeding and child growth was examined prospectively among children under 36 months old who participated in a large cohort study. At baseline and at each of three 6-monthly follow-up visits breastfeeding status was assessed and all subjects were weighed and measured. RESULTS: Undernourished children were more likely to be breastfed for a longer period of time compared with normal children. We found a small difference between breastfed and fully weaned children in the gain in height over the following 6-month period; however, breastfed children were likely to gain significantly less weight, particularly among children who were aged 6-12 months. Similar findings were noted when these associations were examined among children who were normally nourished at the time of breastfeeding assessment. The inverse association between breastfeeding status and weight gain was significantly larger among children of poor or illiterate mothers compared with children of relatively more affluent or literate mothers, respectively. CONCLUSIONS: Our findings suggest that the inverse association is not causal, and may be explained by poorer complementary feeding among breastfed compared with weaned children. Children from poorer households and whose parents are illiterate are more likely to have less than adequate complementary feeding. The importance of adequate complementary feeding in the second half of infancy needs to be stressed in nutrition education programmes.

Body Height↗