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Dive into the research topics where Valentine Yanchou Njike is active.

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Featured researches published by Valentine Yanchou Njike.


Diabetes Care | 2010

Effects of Walnut Consumption on Endothelial Function in Type 2 Diabetic Subjects: A randomized controlled crossover trial

Yingying Ma; Valentine Yanchou Njike; John Millet; Suparna Dutta; Kim Doughty; Judith A. Treu; David L. Katz

OBJECTIVE To determine the effects of daily walnut consumption on endothelial function, cardiovascular biomarkers, and anthropometric measures in type 2 diabetic individuals. RESEARCH DESIGN AND METHODS This study was a randomized, controlled, single-blind, crossover trial. Twenty-four participants with type 2 diabetes (mean age 58 years; 14 women and 10 men) were randomly assigned to one of the two possible sequence permutations to receive an ad libitum diet enriched with 56 g (366 kcal) walnuts/day and an ad libitum diet without walnuts for 8 weeks. Subjects underwent endothelial function testing (measured as flow-mediated dilatation [FMD]) and assessment of cardiovascular biomarkers before and after each 8-week treatment phase. The primary outcome measure was the change in FMD after 8 weeks. Secondary outcome measures included changes in plasma lipids, A1C, fasting glucose, insulin sensitivity, and anthropometric measures. RESULTS Endothelial function significantly improved after consumption of a walnut-enriched ad libitum diet compared with that after consumption of an ad libitum diet without walnuts (2.2 ± 1.7 vs. 1.2 ± 1.6%; P = 0.04). The walnut-enriched diet increased fasting serum glucose and lowered serum total cholesterol and LDL cholesterol from baseline (10.0 ± 20.5 mg/dl, P = 0.04; −9.7 ± 14.5 mg/dl, P < 0.01; and −7.7 ± 10 mg/dl, P < 0.01, respectively), although these changes were not significant compared with those for an ad libitum diet without walnuts. There were no significant changes in anthropometric measures, plasma A1C, and insulin sensitivity. CONCLUSIONS A walnut-enriched ad libitum diet improves endothelium-dependent vasodilatation in type 2 diabetic individuals, suggesting a potential reduction in overall cardiac risk.


The American Journal of Clinical Nutrition | 2010

Performance characteristics of NuVal and the Overall Nutritional Quality Index (ONQI)

David L. Katz; Valentine Yanchou Njike; Lauren Q. Rhee; Arthur Reingold; Keith T. Ayoob

BACKGROUND Improving diets has considerable potential to improve health, but progress in this area has been limited, and advice to increase fruit and vegetable intake has largely gone unheeded. OBJECTIVES Our objective was to test the performance characteristics of the Overall Nutritional Quality Index (ONQI), a tool designed to help improve dietary patterns one well-informed choice at a time. DESIGN The ONQI was developed by a multidisciplinary group of nutrition and public health scientists independent of food industry interests and is the basis for the NuVal Nutritional Guidance System. Dietary guidelines, existing nutritional scoring systems, and other pertinent scientific literature were reviewed. An algorithm incorporating >30 entries that represent both micro- and macronutrient properties of foods, as well as weighting coefficients representing epidemiologic associations between nutrients and health outcomes, was developed and subjected to consumer research and testing of performance characteristics. RESULTS ONQI and expert panel rankings correlated highly (R = 0.92, P < 0.001). In consumer testing, approximately 80% of >800 study participants indicated that the ONQI would influence their purchase intent. ONQI scoring distinguished the more-healthful DASH (Dietary Approaches to Stop Hypertension) diet (mean score: 46) from the typical American diet according to the National Health and Nutrition Examination Survey (NHANES) 2003-2006 (mean score: 26.5; P < 0.01). In linear regression analysis of the NHANES 2003-2006 populations (n = 15,900), the NuVal system was significantly associated with the Healthy Eating Index 2005 (P < 0.0001). Recently generated data from ongoing studies indicate favorable effects on purchase patterns and significant correlation with health outcomes in large cohorts of men and women followed for decades. CONCLUSION NuVal offers universally applicable nutrition guidance that is independent of food industry interests and is supported by consumer research and scientific evaluation of its performance characteristics.


International Journal of Cardiology | 2011

Effects of sugar-sweetened and sugar-free cocoa on endothelial function in overweight adults.

Valentine Yanchou Njike; Zubaida Faridi; Kerem Shuval; Suparna Dutta; Colin D. Kay; Sheila G. West; Penny M. Kris-Etherton; David L. Katz

BACKGROUND Studies of cocoa suggest an array of cardiovascular benefits; however, the effects of daily intake of sugar-free and sugar-sweetened cocoa beverages on endothelial function (EF) have yet to be established. METHODS 44 adults (BMI 25-35 kg/m2) participated in a randomized, controlled, crossover trial. Participants were randomly assigned to a treatment sequence: sugar-free cocoa beverage, sugar-sweetened cocoa beverage, and sugar-sweetened cocoa-free placebo. Treatments were administered daily for 6 weeks, with a 4-week washout period. RESULTS Cocoa ingestion improved EF measured as flow-mediated dilation (FMD) compared to placebo (sugar-free cocoa: change, 2.4% [95% CI, 1.5 to 3.2] vs. -0.8% [95% CI, -1.9 to 0.3]; difference, 3.2% [95% CI, 1.8 to 4.6]; p<0.001 and sugar-sweetened cocoa: change, 1.5% [95% CI, 0.6 to 2.4] vs. -0.8% [95% CI, -1.9 to 0.3]; difference, 2.3% [95% CI, 0.9 to 3.7]; p=0.002). The magnitude of improvement in FMD after consumption of sugar-free versus sugar-sweetened cocoa was greater, but not significantly. Other biomarkers of cardiac risk did not change appreciably from baseline. BMI remained stable throughout the study. CONCLUSIONS Daily cocoa ingestion improves EF independently of other biomarkers of cardiac risk, and does not cause weight gain. Sugar-free preparations may further augment endothelial function.


Health Education Research | 2010

Partners reducing effects of diabetes (PREDICT): a diabetes prevention physical activity and dietary intervention through African-American churches

Zubaida Faridi; Kerem Shuval; Valentine Yanchou Njike; Julie A. Katz; Georgia Jennings; Maurice Williams; David L. Katz

Type 2 diabetes is epidemic in the United States with greater incidence rates in African-American communities. Lifestyle interventions during the phase of insulin resistance mitigate cardiovascular risk and prevent diabetes. The primary aim of this study is to test the impact of a Community Health Advisor (CHA)-based diabetes prevention controlled intervention in urban African-American communities. In this controlled trial, church congregants in New Haven, CT, receiving a 1-year CHA-led diabetes prevention intervention were compared with church congregants in Bridgeport, CT, who did not receive an intervention. Outcome measures included physical activity, dietary pattern, anthropometric measure, social support, diabetes knowledge, nutrition and exercise self-efficacy. The results indicate that at the end of the 1-year intervention period, there were no significant differences observed between intervention and control groups. Possible explanations for the lack of change include difficulty in engaging the CHAs, variability in the CHA-led interventions, baseline discrepancies between the two sites which could not be fully controlled and loss to follow-up. The results indicate important obstacles which impeded the successful implementation of this intervention and lessons learned for future interventions.


American Journal of Public Health | 2013

The Mortality Toll of Estrogen Avoidance: An Analysis of Excess Deaths Among Hysterectomized Women Aged 50 to 59 Years

Philip M. Sarrel; Valentine Yanchou Njike; Valentina Vinante; David L. Katz

OBJECTIVES We examined the effect of estrogen avoidance on mortality rates among hysterectomized women aged 50 to 59 years. METHODS We derived a formula to relate the excess mortality among hysterectomized women aged 50 to 59 years assigned to placebo in the Womens Health Initiative randomized controlled trial to the entire population of comparable women in the United States, incorporating the decline in estrogen use observed between 2002 and 2011. RESULTS Over a 10-year span, starting in 2002, a minimum of 18 601 and as many as 91 610 postmenopausal women died prematurely because of the avoidance of estrogen therapy (ET). CONCLUSIONS ET in younger postmenopausal women is associated with a decisive reduction in all-cause mortality, but estrogen use in this population is low and continuing to fall. Our data indicate an associated annual mortality toll in the thousands of women aged 50 to 59 years. Informed discussion between these women and their health care providers about the effects of ET is a matter of considerable urgency.


Journal of School Health | 2011

Teaching Healthful Food Choices to Elementary School Students and Their Parents: The Nutrition Detectives™ Program†

David L. Katz; Catherine S. Katz; Judith A. Treu; Jesse Reynolds; Valentine Yanchou Njike; Jennifer Walker; Erica Smith; Jennifer Michael

BACKGROUND The purpose of this study was to evaluate the effects of a nutrition education program designed to teach elementary school students and their parents, and to distinguish between more healthful and less healthful choices in diverse food categories. METHODS Three schools were assigned to receive the Nutrition Detectives™ program and 2 comparable schools served as controls. A total of 1180 second, third, and fourth grade elementary school students were included, with 628 students in the intervention and 552 in the control group. The program, delivered by physical education instructors over several sessions totaling less than 2 hours, taught the children how to read food labels and detect marketing deceptions, while learning to identify and choose healthful foods. Parents were introduced to the program through written materials sent home and at school functions. Assessments included a food label quiz, dietary pattern, and body mass index (BMI). RESULTS Students in intervention schools showed a significant increase in nutrition label literacy (p < .01). Third grade students showed the most improvement, 23% (p < .01). The parents of intervention group students also showed a significant increase in nutrition label literacy by 8% (p < .01). Total caloric, sodium, and total sugar intake decreased nonsignificantly among students in the intervention group (p > .05). BMI did not change over the short duration of the study. CONCLUSIONS Nutrition Detectives effectively enhances the ability of students and their parents to identify more nutritious food choices. Further evaluation of the program and its potential to influence dietary pattern, BMI, and health outcomes in students and their families is warranted.


American Journal of Public Health | 2011

From Controlled Trial to Community Adoption: The Multisite Translational Community Trial

David L. Katz; Mary Murimi; Anjelica L. Gonzalez; Valentine Yanchou Njike; Lawrence W. Green

Methods for translating the findings of controlled trials, such as the Diabetes Prevention Program, into real-world community application have not been clearly defined. A standardized research methodology for making and evaluating such a transition is needed. We introduce the multisite translational community trial (mTCT) as the research analog to the multisite randomized controlled trial. The mTCT is adapted to incorporate the principles and practices of community-based participatory research and the increased relevance and generalizability gained from diverse community settings. The mTCT is a tool designed to bridge the gap between what a clinical trial demonstrates can work in principle and what is needed to make it workable and effective in real-world settings. Its utility could be put to the test, in particular with practice-based research networks such as the Prevention Research Centers.


Journal of The American College of Nutrition | 2012

Effects of Walnuts on Endothelial Function in Overweight Adults with Visceral Obesity: A Randomized, Controlled, Crossover Trial

David L. Katz; Anna Davidhi; Yingying Ma; Yasemin Kavak; Lauren Bifulco; Valentine Yanchou Njike

Objectives: Metabolic syndrome is a precursor of diabetes and cardiovascular disease (CVD). Walnut ingestion has been shown to reduce CVD risk indices in diabetes. This randomized controlled crossover trial was performed to investigate the effects of daily walnut consumption on endothelial function and other biomarkers of cardiac risk in a population of overweight individuals with visceral adiposity. Methods: Forty-six overweight adults (average age, 57.4 years; 28 women, 18 men) with elevated waist circumference and 1 or more additional signs of metabolic syndrome were randomly assigned to two 8-week sequences of walnut-enriched ad libitum diet and ad libitum diet without walnuts, which were separated by a 4-week washout period. The primary outcome measure was the change in flow-mediated vasodilation (FMD) of the brachial artery. Secondary measures included serum lipid panel, fasting glucose and insulin, Homeostasis Model Assessment–Insulin Resistance values, blood pressure, and anthropometric measures. Results: FMD improved significantly from baseline when subjects consumed a walnut-enriched diet as compared with the control diet (1.4% ± 2.4% versus 0.3% ± 1.5%; p = 0.019). Beneficial trends in systolic blood pressure reduction were seen, and maintenance of the baseline anthropometric values was also observed. Other measures were unaltered. Conclusion: Daily ingestion of 56 g of walnuts improves endothelial function in overweight adults with visceral adiposity. The addition of walnuts to the diet does not lead to weight gain. Further study of the potential role of walnut intake in diabetes and CVD prevention is warranted.


American Journal of Health Promotion | 2009

The Stratification of Foods on the Basis of Overall Nutritional Quality: The Overall Nutritional Quality Index

David L. Katz; Valentine Yanchou Njike; Zubaida Faridi; Lauren Q. Rhee; Rebecca S. Reeves; David J. A. Jenkins; Keith T. Ayoob

Purpose. Consumer understanding of nutrition information is key to making dietary choices consistent with guidelines. The development of an objective, science-based, and universally applicable system of nutrition guidance would be of considerable potential value to the public health. Design. A multidisciplinary expert panel was convened to develop the Overall Nutritional Quality Index (ONQI). Dietary guidelines, existing nutritional scoring systems, and other pertinent scientific literature were reviewed. An algorithm based on the overall nutritional quality of food was developed and subjected to consumer research and validation testing. Results. The ONQI algorithm incorporates over 30 entries representing both micronutrient and macronutrient properties of foods, as well as weighting coefficients representing epidemiologic associations between nutrients and health outcomes. The basic entry in the algorithm is a weighted trajectory score, which compares nutrient concentration in a food to the recommended concentration of a given nutrient in a healthful diet. In content validity testing, ONQI rankings and expert panel rankings correlated highly (R = .92; p < .001). In regression analysis, aggregated ONQI scores for total diet corresponded well with the Healthy Eating Index (p < .001) in the National Health and Nutrient Examination Survey 2003–2006 cohort (n = 15,900). Consumer research indicated strong appeal to consumers of the ONQI system in general, and the scores on a 1 to 100 scale specifically. A system for acquiring nutrient data, meeting U.S. Food and Drug Administration and U.S. Department of Agriculture standards, has been established so that virtually any food, beverage, meal, or recipe can be scored. Conclusions. The ONQI is a sophisticated nutrition guidance system developed by a multidisciplinary group independently of all food industry interests with excellent initial performance in both consumer research and validation testing. Combined with a consumer education program, the ONQI has considerable potential to improve dietary patterns, and consequently the public health. Prospective study of effects on dietary patterns and health outcomes is warranted.


PLOS ONE | 2012

Massage therapy for osteoarthritis of the knee: a randomized dose-finding trial.

Adam Perlman; Ather Ali; Valentine Yanchou Njike; David L. Hom; Anna Davidi; Susan Gould-Fogerite; Carl Milak; David L. Katz

Background In a previous trial of massage for osteoarthritis (OA) of the knee, we demonstrated feasibility, safety and possible efficacy, with benefits that persisted at least 8 weeks beyond treatment termination. Methods We performed a RCT to identify the optimal dose of massage within an 8-week treatment regimen and to further examine durability of response. Participants were 125 adults with OA of the knee, randomized to one of four 8-week regimens of a standardized Swedish massage regimen (30 or 60 min weekly or biweekly) or to a Usual Care control. Outcomes included the Western Ontario and McMaster Universities Arthritis Index (WOMAC), visual analog pain scale, range of motion, and time to walk 50 feet, assessed at baseline, 8-, 16-, and 24-weeks. Results WOMAC Global scores improved significantly (24.0 points, 95% CI ranged from 15.3–32.7) in the 60-minute massage groups compared to Usual Care (6.3 points, 95% CI 0.1–12.8) at the primary endpoint of 8-weeks. WOMAC subscales of pain and functionality, as well as the visual analog pain scale also demonstrated significant improvements in the 60-minute doses compared to usual care. No significant differences were seen in range of motion at 8-weeks, and no significant effects were seen in any outcome measure at 24-weeks compared to usual care. A dose-response curve based on WOMAC Global scores shows increasing effect with greater total time of massage, but with a plateau at the 60-minute/week dose. Conclusion Given the superior convenience of a once-weekly protocol, cost savings, and consistency with a typical real-world massage protocol, the 60-minute once weekly dose was determined to be optimal, establishing a standard for future trials. Trial Registration ClinicalTrials.gov NCT00970008

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