"iDoctor – Medical Blog"

Publication year: 2009
Source: The American Journal of Cardiology, In Press, Corrected Proof, Available online 26 November 2009
Hidekazu, Tanaka , Hideyuki, Hara , Samir, Saba , John, Gorcsan III

Previous methods to quantify dyssynchrony could not determine regional 3-dimensional (3-D) strain. We hypothesized that a novel 3-D speckle tracking strain imaging system can quantify left ventricular (LV) dyssynchrony and site of latest mechanical activation. We studied 64 subjects; 54 patients with heart failure were referred for cardiac resynchronization therapy (CRT) with an ejection fraction 25 ± 6% and QRS interval 165 ± 29 ms and 10 healthy volunteer controls. The 3-D speckle tracking system determined radial strain using a 16-segment model from a pyramidal 3-D dataset. Dyssynchrony was quantified as maximal opposing wall delay and SD in time to…

Purpose: This study aimed to evaluate the efficacy of photodynamic therapy (PDT) in treating chronic central serous chorioretinopathy (CSC).Methods: We describe a non-randomized, multicentre, interventional case series. A total of 82 eyes of 72 patients with chronic CSC were treated by conventional PDT. LogMAR best corrected visual acuity (BCVA) (ETDRS charts) and central foveal thickness (CFT) measured by optical coherence tomography before and after PDT, number of PDT treatments and complications were used as outcome indicators.Results: Mean follow-up was 12 ± 10 months and mean age was 46 ± 10 years. Mean logMAR BCVA changed from 0.53 (standard deviation [SD] 0.43) before PDT to 0.38 (SD 0.41) at 3 months and 0.48 (SD 0.50) at 6 months (p < 0.0001 and p = 0.007, respectively, Student’s t-test for paired data). Mean BCVA at the end of follow-up was 0.37 (SD 0.45; p < 0.0001 from baseline). Macular detachment was resolved and subretinal fluid (SRF) disappeared in all cases. Central foveal thickness decreased from 325 [mu]m (SD 95), to 229 [mu]m (SD 70) at 1 month after PDT, 206 [mu]m (SD 68) at 3 months, and 202 [mu]m (SD 76) at 6 months (all p < 0.0001, Student’s t-test for paired data). No cases developed severe visual loss or complications derived from PDT. Reactive retinal pigment epithelium hypertrophy appeared in nine cases after PDT.Conclusions: Photodynamic therapy with verteporfin may be useful in chronic CSC for improving BCVA and reducing SRF and CFT. Randomized studies with longer follow-up are needed to assess the real role of this treatment in chronic CSC.

Individual diet modeling translates nutrient recommendations into realistic and individual-specific food choices.

Am J Clin Nutr. 2009 Nov 25;

Authors: Maillot M, Vieux F, Amiot J, Darmon N

BACKGROUND: Nutrient-based recommendations are defined for populations, but the dietary choices needed to fulfill them at the individual level deserve further exploration. OBJECTIVE: The objective was to describe the dietary changes needed to achieve nutritional recommendations for each individual of a population. DESIGN: An individual diet model was specifically developed for each adult participating in the French national INCA (Enquête Individuelle et Nationale sur les Consommations Alimentaires) dietary survey (n = 1171). Starting from each individual weekly food intake (observed diets), an isocaloric modeled diet was designed by linear programming to simultaneously meet the French nutrient recommendations for 32 nutrients while deviating the least from the observed food intake. Modeled diets were paired with observed diets for statistical comparison. RESULTS: A new nutritionally adequate diet was obtained for each individual. In half the modeled diets, <5 of the foods usually consumed were replaced. The amount of foods selected in the modeled diets varied from individual to individual, and this variability followed that found in observed diets. Fruit, vegetables, grains, legumes, dried fruit, unsalted nuts, fresh dairy products, and fish were increased in modeled diets. Fatty fish and walnuts were added to each modeled diet. In contrast, red meats, deli meats, cheese, mixed dishes, and salted snacks were decreased. Sweets were also decreased but to a lesser extent. CONCLUSIONS: This new individual diet modeling approach offers the possibility of translating nutrient recommendations into realistic food choices for all individuals from a representative population. The results showed that nutrient needs can be fulfilled in many different ways, depending on initial individual food patterns.

PMID: 19939986 [PubMed - as supplied by publisher]

A randomized trial to determine the optimal dosage of multivitamin supplements to reduce adverse pregnancy outcomes among HIV-infected women in Tanzania.

Am J Clin Nutr. 2009 Nov 25;

Authors: Kawai K, Kupka R, Mugusi F, Aboud S, Okuma J, Villamor E, Spiegelman D, Fawzi WW

BACKGROUND: We previously reported that supplementation with multivitamins (vitamin B complex, vitamin C, and vitamin E) at multiples of the Recommended Dietary Allowance (RDA) significantly decreased the risk of adverse pregnancy outcomes among HIV-infected women. The minimum dosage of multivitamins necessary for optimal benefits is unknown. OBJECTIVE: We investigated the efficacy of multivitamin supplements at single compared with multiple RDAs on decreasing the risk of adverse pregnancy outcomes among HIV-infected women. DESIGN: We conducted a double-blind, randomized controlled trial among 1129 HIV-infected pregnant women in Tanzania. Eligible women between 12 and 27 gestational weeks were randomly assigned to receive daily oral supplements of either single or multiple RDA multivitamins from the enrollment until 6 wk after delivery. RESULTS: Multivitamins at multiple and single doses of the RDA had similar effects on the risk of low birth weight (11.6% and 10.2%, respectively; P = 0.75). We found no difference between the 2 groups in the risk of preterm birth (19.3% and 18.4%, respectively; P = 0.73) or small-for-gestational-age (14.8% and 12.0%, respectively; P = 0.18). The mean birth weights were similar in the multiple RDA (3045 +/- 549 g) and single RDA multivitamins group (3052 +/- 534 g; P = 0.83). There were no significant differences between the 2 groups in the risk of fetal death (P = 0.99) or early infant death (P = 0.19). CONCLUSION: Multivitamin supplements at a single dose of the RDA may be as efficacious as multiple doses of the RDA in decreasing the risk of adverse pregnancy outcomes among HIV-infected women. This trial was registered at clinicaltrials.gov as NCT00197678.

PMID: 19939985 [PubMed - as supplied by publisher]

Cardiovascular disease risk of dietary stearic acid compared with trans, other saturated, and unsaturated fatty acids: a systematic review1,3.

Am J Clin Nutr. 2009 Nov 25;

Authors: Hunter JE, Zhang J, Kris-Etherton PM

BACKGROUND: High stearic acid (STA) soybean oil is a trans-free, oxidatively stable, non-LDL-cholesterol-raising oil that can be used to replace trans fatty acids (TFAs) in solid fat applications. OBJECTIVE: The objective was to assess the cardiovascular health effects of dietary STA compared with those of trans, other saturated, and unsaturated fatty acids. DESIGN: We reviewed epidemiologic and clinical studies that evaluated the relation between STA and cardiovascular disease (CVD) risk factors, including plasma lipids and lipoproteins, hemostatic variables, and inflammatory markers. RESULTS: In comparison with other saturated fatty acids, STA lowered LDL cholesterol, was neutral with respect to HDL cholesterol, and directionally lowered the ratio of total to HDL cholesterol. STA tended to raise LDL cholesterol, lower HDL cholesterol, and increase the ratio of total to HDL cholesterol in comparison with unsaturated fatty acids. In 2 of 4 studies, high-STA diets increased lipoprotein(a) in comparison with diets high in saturated fatty acids. Three studies showed increased plasma fibrinogen when dietary STA exceeded 9% of energy (the current 90th percentile of intake is 3.5%). Replacing industrial TFAs with STA might increase STA intake from 3.0% (current) to approximately 4% of energy and from 4% to 5% of energy at the 90th percentile. One-to-one substitution of STA for TFAs showed a decrease or no effect on LDL cholesterol, an increase or no effect on HDL cholesterol, and a decrease in the ratio of total to HDL cholesterol. CONCLUSIONS: TFA intake should be reduced as much as possible because of its adverse effects on lipids and lipoproteins. The replacement of TFA with STA compared with other saturated fatty acids in foods that require solid fats beneficially affects LDL cholesterol, the primary target for CVD risk reduction; unsaturated fats are preferred for liquid fat applications. Research is needed to evaluate the effects of STA on emerging CVD risk markers such as fibrinogen and to understand the responses in different populations.

PMID: 19939984 [PubMed - as supplied by publisher]

Methionine metabolism in human pregnancy.

Am J Clin Nutr. 2009 Nov 25;

Authors: Dasarathy J, Gruca LL, Bennett C, Parimi PS, Duenas C, Marczewski S, Fierro JL, Kalhan SC

BACKGROUND: Hyperhomocysteinemia during pregnancy, which is a consequence of perturbations in methionine and/or folate metabolism, has been implicated in adverse outcomes such as neural tube defects, preeclampsia, spontaneous abortion, and premature delivery. The adaptive changes in methionine metabolism during pregnancy in humans have not been determined. OBJECTIVE: Our objective was to examine the kinetics of methionine and its rate of transsulfuration and transmethylation in healthy women with advancing gestation. DESIGN: The whole-body rate of appearance (Ra) of methionine and phenylalanine was measured in healthy pregnant women during the first (n = 10), second (n = 5), and third (n = 10) trimesters of pregnancy. These data were compared with those for nonpregnant women (n = 8). Tracers [1-(13)C]methionine, [C(2)H(3)]methionine, and [(2)H(5)]phenylalanine were administered as prime-constant rate infusions. The effect of enteral high-protein, mixed-nutrient load on tracer-determined variables was also examined. RESULTS: In pregnant women, the Ra of phenylalanine was significantly (P < 0.05) lower in the first trimester compared with the second and third trimesters and compared with that in nonpregnant women. A linear positive correlation was evident between gestational age and phenylalanine Ra. The fractional rate and total rate of transsulfuration of methionine was significantly (P < 0.05) higher during the first trimester, whereas the rate of transmethylation was higher during the third trimester. Plasma concentrations of total cysteine and homocysteine were lower during pregnancy. CONCLUSIONS: Uncomplicated pregnancy in humans is associated with a higher rate of transsulfuration early in gestation and a higher rate of transmethylation of methionine in late gestation. These data may have implications for understanding the role of methionine and homocysteine in complications of pregnancy and for the nutritional care of pregnant women.

PMID: 19939983 [PubMed - as supplied by publisher]

Differential epigenomic and transcriptomic responses in subcutaneous adipose tissue between low and high responders to caloric restriction.

Am J Clin Nutr. 2009 Nov 25;

Authors: Bouchard L, Rabasa-Lhoret R, Faraj M, Lavoie ME, Mill J, Pérusse L, Vohl MC

BACKGROUND: Caloric restriction is recommended for the treatment of obesity, but it is generally characterized by large interindividual variability in responses. The factors affecting the magnitude of weight loss remain poorly understood. Epigenetic factors (ie, heritable but reversible changes to genomic function that regulate gene expression independently of DNA sequence) may explain some of the interindividual variability seen in weight-loss responses. OBJECTIVE: The objective was to determine whether epigenetics and gene expression changes may play a role in weight-loss responsiveness. DESIGN: Overweight/obese postmenopausal women were recruited for a standard 6-mo caloric restriction intervention. Abdominal subcutaneous adipose tissue biopsy samples were collected before (n = 14) and after (n = 14) intervention, and the epigenomic and transcriptomic profiles of the high and low responders to dieting, on the basis of changes in percentage body fat, were compared by using microarray analysis. RESULTS: Significant DNA methylation differences at 35 loci were found between the high and low responders before dieting, with 3 regions showing differential methylation after intervention. Some of these regions contained genes known to be involved in weight control and insulin secretion, whereas others were localized in known imprinted genomic regions. Differences in gene expression profiles were observed only after dieting, with 644 genes being differentially expressed between the 2 groups. These included genes likely to be involved in metabolic pathways related to angiogenesis and cerebellar long-term depression. CONCLUSIONS: These data show that both DNA methylation and gene expression are responsive to caloric restriction and provide new insights about the molecular pathways involved in body weight loss as well as methylation regulation during adulthood.

PMID: 19939982 [PubMed - as supplied by publisher]

Defining the genetic architecture of the predisposition to obesity: a challenging but not insurmountable task.

Am J Clin Nutr. 2009 Nov 25;

Authors: Bouchard C

PMID: 19939981 [PubMed - as supplied by publisher]

Purpose: To determine the natural end-point for refractive development during childhood.Methods: Cycloplegic (1% cyclopentolate) autorefraction was performed on 38 811 children aged 5 and 15 in population-based samples at eight sites in the Refractive Error Study in Children (RESC). Refractions (right eye) were categorized as myopic ([le][minus]0.5 D), emmetropic (>[minus]0.5 to [le]+0.5 D), mildly hyperopic (>+0.5 to [le]+2.0 D and hyperopic (>+2.0 D).Results: At five sites (Jhapa [ndash] rural Nepal, New Delhi [ndash] urban India, Mahabubnagar [ndash] rural India, Durban [ndash] semi-urban South Africa and La Florida [ndash] urban Chile), there was <20% myopia by age 15. Mild hyperopia was the most prevalent category at all ages, except for Mahabubnagar where emmetropia became the marginally most prevalent category at ages 14 and 15. At the other sites (Gombak [ndash] semi-urban Malaysia, Shunyi [ndash] semi-rural China and Guangzhou [ndash] urban China), there was substantial (>35%) myopia by age 15. At these sites, mild hyperopia was the most prevalent category during early childhood, and myopia became the predominant category later. In Gombak district and Guangzhou, emmetropia was a minor category at all ages, with myopia increasing as mild hyperopia decreased. In Shunyi district, emmetropia was the most prevalent category over the ages 11[ndash]14.Conclusion: Emmetropia was not the predominant outcome for refractive development in children. Instead, populations were predominantly mildly hyperopic or substantial amounts of myopia appeared in them. This suggests that mild hyperopia is the natural state of refractive development in children and that emmetropia during childhood carries the risk of subsequent progression to myopia.