Effects of walnut consumption on blood lipids and other cardiovascular risk factors: a meta-analysis and systematic review.

BACKGROUND: Consumption of nuts has been associated with a decreased risk of cardiovascular disease events and death. Walnuts in particular have a unique profile: they are rich in polyunsaturated fatty acids, which may improve blood lipids and other cardiovascular disease risk factors. OBJECTIVES: We aimed to conduct a literature review and a meta-analysis to combine the results from several trials and to estimate the effect of walnuts on blood lipids. DESIGN: Literature databases were searched for published trials that compared a specifically walnut-enhanced diet with a control diet. We conducted a random-effects meta-analysis of weighted mean differences (WMDs) of lipid outcomes. RESULTS: Thirteen studies representing 365 participants were included in the analysis. Diets lasted 4-24 wk with walnuts providing 10-24% of total calories. When compared with control diets, diets supplemented with walnuts resulted in a significantly greater decrease in total cholesterol and in LDL-cholesterol concentrations (total cholesterol: WMD = -10.3 mg/dL, P < 0.001; LDL cholesterol: WMD = -9.2 mg/dL, P < 0.001). HDL cholesterol and triglycerides were not significantly affected by walnut diets more than with control diets (HDL cholesterol: WMD = -0.2, P = 0.8; triglycerides: WMD = -3.9, P = 0.3). Other results reported in the trials indicated that walnuts provided significant benefits for certain antioxidant capacity and inflammatory markers and had no adverse effects on body weight [body mass index (kg/m(2)): WMD = -0.4, P = 0.5; weight (kg): WMD = -0.05, P = 0.97]. CONCLUSIONS: Overall, high-walnut-enriched diets significantly decreased total and LDL cholesterol for the duration of the short-term trials. Larger and longer-term trials are needed to address the effects of walnut consumption on cardiovascular risk and body weight.

Weight and type 2 diabetes after bariatric surgery: systematic review and meta-analysis.

BACKGROUND: The prevalence of obesity-induced type 2 diabetes mellitus is increasing worldwide. The objective of this review and meta-analysis is to determine the impact of bariatric surgery on type 2 diabetes in association with the procedure performed and the weight reduction achieved. METHODS: The review includes all articles published in English from January 1, 1990, to April 30, 2006. RESULTS: The dataset includes 621 studies with 888 treatment arms and 135,246 patients; 103 treatment arms with 3188 patients reported on resolution of diabetes, that is, the resolution of the clinical and laboratory manifestations of type 2 diabetes. Nineteen studies with 43 treatment arms and 11,175 patients reported both weight loss and diabetes resolution separately for the 4070 diabetic patients in these studies. At baseline, the mean age was 40.2 years, body mass index was 47.9 kg/m2, 80% were female, and 10.5% had previous bariatric procedures. Meta-analysis of weight loss overall was 38.5 kg or 55.9% excess body weight loss. Overall, 78.1% of diabetic patients had complete resolution, and diabetes was improved or resolved in 86.6% of patients. Weight loss and diabetes resolution were greatest for patients undergoing biliopancreatic diversion/duodenal switch, followed by gastric bypass, and least for banding procedures. Insulin levels declined significantly postoperatively, as did hemoglobin A1c and fasting glucose values. Weight and diabetes parameters showed little difference at less than 2 years and at 2 years or more. CONCLUSION: The clinical and laboratory manifestations of type 2 diabetes are resolved or improved in the greater majority of patients after bariatric surgery; these responses are more pronounced in procedures associated with a greater percentage of excess body weight loss and is maintained for 2 years or more.

Ultrasonic and nonultrasonic instrumentation: a systematic review and meta-analysis.

OBJECTIVE: To compare the efficacy and safety of ultrasonic surgical instrumentation with nonultrasonic traditional surgical techniques in various types of surgery. DATA SOURCES: Electronic searches of MEDLINE, Current Contents, and the Cochrane Library were performed for the period of 1990 to June 1, 2005, using relevant search terms. A manual check of all references in accepted studies was also performed. STUDY SELECTION: Only comparative studies (including randomized and nonrandomized control trials) of ultrasonic surgical instrumentation with nonultrasonic instrumentation were accepted. Procedures of interest included the following: colorectal surgery, gynecologic surgery, head and neck surgery, solid organ surgery, vessel harvesting, cholecystectomy, hemorrhoidectomy, mastectomy, and Nissen fundoplication. DATA EXTRACTION: Two investigators reviewed each study: the first investigator extracted all relevant data, and consensus of each extraction was performed by a second investigator to verify the data. Data were then entered into a database and quality checked for accuracy. DATA SYNTHESIS: Fifty-one primary studies that examined 4902 patients were included in this systematic review, of which 24 were randomized trials and 27 were nonrandomized studies. Comparative meta-analyses for blood loss, surgery time, and hospital length of stay were performed using a random-effects model and stratified by surgery type. Heterogeneity was tested using Q statistics. Statistical significance was defined as P < .05. CONCLUSION: Meta-analysis of outcomes comparing ultrasonic with conventional nonultrasonic surgical instrumentation demonstrates significant improvement of several perioperative outcomes in procedure-specific settings when ultrasonic instrumentation is used.

Studies of Swedish adjustable gastric band and Lap-Band: systematic review and meta-analysis.

BACKGROUND: This is the first systematic review and meta-analysis of the large body of data describing the Swedish adjustable gastric band (SAGB) and Lap-Band (LB). METHODS: A systematic review was performed that included screening of studies published in any language (January 1, 1998 through April 30, 2006) identified through MEDLINE, Current Contents, or the Cochrane Library. Studies with > or =10 SAGB or LB patients reporting > or =30-day efficacy or safety outcomes were eligible for review; the data were extracted from the accepted studies. A weighted means analysis and random-effects meta-analysis of efficacy outcomes of interest were conducted. RESULTS: A total of 4592 bariatric surgery studies met the initial criteria. Of these studies, 129 (28,980 patients) were accepted (33 SAGB and 104 LB studies); most had a retrospective single-center design. For 4273 patients (36 treatment groups) in 33 SAGB studies and 24,707 patients (111 groups) in 104 LB studies, the mean baseline age (39.1-40.2 yr), body mass index (43.8-45.3 kg/m2), and gender (women 79.2-82.5%) were similar. A laparoscopic technique was used in > or =88% and a pars flaccida technique in > or =41% of both groups. Early mortality was equivalent for SAGB/LB (< or =.1%). The 3-year mean SAGB and LB excess weight loss (56.36% and 50.20%, respectively) and body mass index reduction (-11.99 and -11.81 kg/m2, respectively) from baseline were statistically significant (P <.05), as was the resolution of diabetes (61.45% and 60.29%, respectively) and hypertension (62.95% and 43.58%, respectively). Although scant and inconsistently reported data precluded direct statistical comparisons, the complication rates for the 2 devices appeared comparable. In 8 directly comparative studies, meta-analysis found a significantly greater absolute weight loss (P <.05) with the SAGB at 2 years (48.4 versus 41.9 kg, mean difference -4.84, 95% confidence interval -9.47 to -0.22), although no difference was found in the percentage of excess weight loss or change in body mass index. CONCLUSION: In a systematic review of the published world SAGB and LB data, at 1, 2, and 3 years, the weight loss, resolution of diabetes and hypertension, and complications appeared comparable.

Meta-analysis of alignment outcomes in computer-assisted total knee arthroplasty surgery.

Computer-assisted surgery (CAS) has been advocated as a means to improve limb and prosthesis alignment and assist in ligament balancing in total knee arthroplasty (TKA). Thus, we sought to examine alignment outcomes in CAS vs conventional TKA. A systematic review of literature from 1990 to 2007 was performed. Direct comparison of alignment outcomes was performed using random effects meta-analyses. Twenty-nine studies of CAS vs conventional TKA were identified, and included mechanical axis malalignment of greater than 3 degrees occurred in 9.0% of CAS vs 31.8% of conventional TKA patients. The risk of greater than 3 degrees malalignment was significantly less with CAS than conventional techniques for mechanical axis and frontal plane femoral and tibial component alignment. Tibial and femoral slope both showed statistical significance in favor of CAS at greater than 2 degrees malalignment. Meta-analysis of alignment outcomes for CAS vs conventional TKA indicates significant improvement in component orientation and mechanical axis when CAS is used.

Trends in mortality in bariatric surgery: a systematic review and meta-analysis.

BACKGROUND: This is the first systematic review and meta-analysis of published mortality data after bariatric surgery. METHODS: The review includes all papers published in English from January 1, 1990 to April 30, 2006, identified through electronic searches in MEDLINE, Current Contents, and the Cochrane Library, supplemented by manual reference checks. All accepted studies were assigned a level of evidence (Centre for Evidence-Based Medicine, Oxford, UK), and randomized controlled trials were rated for quality using the Jadad scoring method. Random effects meta-analyses were performed. Mortality was analyzed at either 30 days to 2 years was 0.35% (95% CI, 0.12-0.58) in 140 treatment arms (n = 19,928). Mortality at or=65 years). CONCLUSION: The early and late mortality rates after bariatric surgery are low and can be subjected to risk stratification for comparative analyses and prospective risk assessments.