Well-matched Cohort Research Articles

Basal metabolic rate in morbidly obese patients with non-alcoholic fatty liver disease

Non-Alcoholic Fatty Liver Disease occurs mainly in severly obese patients and its relationship to Metabolic Syndrome is increasingly recognized. The aim of this study was to determine energy production-utilization by measuring the Basal Metabolic Rate in severely obese patients, characterized by NAFLD, with or without Metabolic Syndrome. Then, the role of systemic inflammation was assessed. Twenty severly obese men with Metabolic Syndrome were compared with a well-matched cohort of patients without Metabolic Syndrome. All showed hepatic steatosis at UltraSonography. Basal Metabolic Rate was measured by indirect calorimetry using a canopy system and single-frequency bio-impedance analysis. Serum Interleukin-6 and fibrinogen levels were measured as markers of inflammation Basal Metabolic Rate was higher in severely obese patients with Metabolic Syndrome than in those without it: 2,496+/-358 kcal/d vs 2,126+/-253 kcal/d, P = 0 .001. Laboratory findings of concurrent chronic inflammation were also higher in these patients, i.e., Il6 4.35+/-1.34 pg/ml vs 6.23+/-2.1 pg/ml, P = 0.034; fibrinogenemia 285+/-40 mg/dL vs 376+/-91 mg/dL, P = 0.020; these of of cytonecrosis, i.e., AlaninaminoTransferase, equally behaved 32.3+/-7.9 UI vs 65.7+/-28.2 UI, P < 0.001. Visceral adiposity and arterial hypertension were more frequently detected in patients with Metabolic Syndrome. Increased energy expenditure, observed in morbidly obese patients as a consequence of a systemic, low-grade, inflammatory process, may explain progression from obesity to Metabolic Syndrome, independent of the presence of NAFLD. In this context, increased Basal Metabolic Rate may be a clue of Metabolic Syndrome.

Endovascular stent grafting versus open surgical repair of descending thoracic aortic aneurysms in low-risk patients: A multicenter comparative trial

Results are presented from the first completed multicenter trial directed at gaining approval from the US Food and Drug Administration of endovascular versus open surgical repair of descending thoracic aortic aneurysms. Between September 1999 and May 2001, 140 patients with descending thoracic aneurysms were enrolled at 17 sites and evaluated for a Gore TAG Thoracic Endograft. An open surgical control cohort of 94 patients was identified by enrolling historical and concurrent subjects. Patients were assessed before treatment, at treatment, and at hospital discharge and returned for follow-up visits at 1 month, 6 months, and annually thereafter. One hundred thirty-seven of 140 patients had successful implantation of the endograft. Perioperative mortality in the endograft versus open surgical control cohort was 2.1% (n = 3) versus 11.7% (n = 11, P < .001). Thirty-day analysis revealed a statistically significant lower incidence of the following complications in the endovascular cohort versus the surgical cohort: spinal cord ischemia (3% vs 14%), respiratory failure (4% vs 20%), and renal insufficiency (1% vs 13%). The endovascular group had a higher incidence of peripheral vascular complications (14% vs 4%). The mean lengths of intensive care unit stay (2.6 +/- 14.6 vs 5.2 +/- 7.2 days) and hospital stay (7.4 +/- 17.7 vs 14.4 +/- 12.8 days) were significantly shorter in the endovascular cohort. At 1 and 2 years' follow-up, the incidence of endoleaks was 6% and 9%, respectively. Through 2 years of follow-up, there were 3 reinterventions in the endograft cohort and none in the open surgical control cohort. Kaplan-Meier analysis revealed no difference in overall mortality at 2 years. In this multicenter study early outcomes with descending aortic endovascular stent grafting were very encouraging when compared with those of a well-matched surgical cohort. However, at 2 years' follow-up, there is an incidence of endoleaks and reinterventions associated with endovascular versus open surgical repair. Continued vigilant surveillance of patients treated with an endograft is important.

Prior Therapy with Rituximab (R) in Patients with Follicular Lymphoma (FL) Does Not Affect Relapse-Free (RFS) or Overall Survival (OS) after High Dose Therapy (HDT) and Autologous Stem Cell Transplantation (ASCT).

ASCT has been used in FL to achieve durable remissions either as consolidation therapy in first remission or as salvage therapy in the relapsed or refractory setting. The recent addition of R to chemotherapy regimens for FL has been shown to improve RFS and, in some studies, OS. The effectiveness of HDT and ASCT in pts with FL who have received prior therapy with R is unknown, although there is speculation that R may adversely affect outcome.We retrospectively reviewed 128 consecutive patients with FL who underwent HDT and ASCT from 1/1994 through 12/2004. The analysis included 106 patients who were divided into No R and R groups. We excluded 19 patients who received R only as salvage therapy and three patients who received bone marrow rather than stem cells as their auto-graft. Patients were analyzed according to whether or not they had received an R-containing regimen prior to transplantation.71 patients with No R therapy and 35 patients with R therapy were included. Characteristics between No R and R group are similar, with major difference being age, CD34+ dose, and length of follow-up. The No R group had a median OS that was not reached during follow up, with a median RFS of 49.9 months. The R group had a median OS of 63.2 months and a median RFS of 24.6 months. The OS and RFS were not significantly different between the groups. To control for potentially confounding factors between cohorts, we used propensity analysis to identify 22 patients among the R group who were well-matched to 22 patients in the No R group. Analysis was done for this well-matched cohort (Table 1), and OS and PFS were also found to have no significant difference (Figures 1 and 2).In conclusion, we did not observe a difference in outcome in the effectiveness of HDT and ASCT between FL patients who received R therapy and those who did not. Prospective studies are required to confirm these results.Table 1Matched Groups by Rituximab UseNo RituximabRituximabN%N%Age (years)mean +/− SD49 +/− 859 +/− 7median (range)51 (28–69)59 (49–75)StageI/II48.2323.1III816.3215.4IV3775.5861.5# of Prior Chemotherapmean +/− SD2.4 +/− 1.03.1 +/− 1.7median (range)2 (1–5)2 (1–7)IPILow, Low-Int2959.213100High-Int, High2040.800.0 [Display omitted] [Display omitted]

Thematic review series: Patient-Oriented Research. Dietary fat, carbohydrate, and protein: effects on plasma lipoprotein patterns

In general, under isoweight conditions, different types of dietary protein or individual amino acids have little effect on lipoprotein patterns. Dietary carbohydrate tends to increase plasma triglyceride when it displaces fat, accompanied by a decrease in HDL cholesterol concentrations. Potential differential effects of types of carbohydrate are difficult to assess because of differences in rates of absorption and confounding of dietary fiber. Saturated fatty acids increase LDL and HDL cholesterol, whereas trans fatty acids increase LDL but not HDL cholesterol. Unsaturated fatty acids decrease LDL and HDL cholesterol, polyunsaturated more so than monounsaturated. There has been considerable interest in the potential benefit of major shifts in dietary macronutrients on weight loss and lipoprotein patterns. Short-term data favor substituting protein and fat for carbohydrate, whereas long-term data have failed to show a benefit for weight loss. During an active weight loss period low-carbohydrate diets more favorably affect triglyceride and HDL and less favorably affect LDL cholesterol concentrations. Additional efforts need to be focused on gaining a better understanding of the effect of dietary macronutrient profiles on established and emerging cardiovascular disease risk factors, mechanisms for changes observed and contributors to individual variability. Such data are needed to allow reassessment and, if necessary, modification of current recommendations.

Assessment of Treatment Responses to Dental Flossing in Twins

The purpose of this study was to assess treatment responses to dental flossing in twins. The study was a two-treatment, examiner-blind, randomized parallel group, controlled study. Fifty-one twin pairs between 12 and 21 years of age were randomized to a 2-week supervised and unsupervised treatment regimen consisting of 1) tongue brushing and toothbrushing (TB) and 2) TB + flossing (TB + Fl). Clinical endpoints were gingival bleeding (papillary bleeding score [PBS]) and oral malodor (levels of volatile sulfur compounds [VSC]). Analysis of variance and covariance methodologies were employed to analyze the data. Baseline average PBS values were 1.352 and 1.345 for the TB + Fl and TB groups, respectively (P=0.937). After 2 weeks of treatment, the TB + Fl group had a statistically significant decrease in PBS values of 0.558 (41.5% versus baseline), whereas the TB group showed no improvement from baseline. The change from baseline for the TB + Fl group was superior to that for the TB group (P<0.001). Similar findings were observed for the number of baseline papillary bleeding sites. Baseline average intraoral halimeter values were 45.91 and 41.75 for the TB+Fl and TB groups, respectively (P=0.504). Both treatment regimens demonstrated highly statistically significant reductions in intraoral halimeter values versus baseline (all P<0.001) and the difference between treatment groups was not statistically significant (P=0.339). Similar findings were found for expired air. In a well-matched twin cohort, tongue and toothbrushing plus flossing significantly decreased gingival bleeding after 2 weeks.

Hepatitis C infection with normal transaminases: Is the treatment worse than the disease?

Hepatitis C infection with normal transaminases: Is the treatment worse than the disease?

Does limited placement of bioresorbable membrane of modified sodium hyaluronate and carboxymethylcellulose (Seprafilm) have possible short-term beneficial impact?

The aim of the study was to assess the impact of sodium hyaluronate and carboxymethylcellulose membrane (Seprafilm) on postoperative intestinal obstruction as judged by the rates of bowel obstruction and laparotomy for bowel obstruction. A secondary aim was to assess early postoperative morbidity. All patients who had Seprafilm placed during colorectal surgery between June 1993 and October 1998 were included in the study group and compared with a matched group of patients without Seprafilm. All patients were assessed for intestinal obstruction and complications by telephone interview and chart review. Statistical tests for independence were used where appropriate; alpha was 0.05 for all tests, and the two groups were tested for case matching. Fisher's exact test was used to compare gender distribution, nature of diagnosis (inflammatory vs. noninflammatory), and urgency of surgery (elective vs. emergency). The age distribution, number of prior abdominal surgeries, and operative time were compared by Student's t-test. Approximation of Katz test was used for independent proportions to compare the two groups for early postoperative morbidity and overall incidence of intestinal obstruction and surgical enterolysis. The incidence of intestinal obstruction between the two groups was also compared with Kaplan-Meier product limit method and log-rank test. Two hundred fifty-nine patients in whom Seprafilm was placed were compared with a well-matched control cohort of 179 patients. The two groups did not differ in gender or age. One-half of each group had inflammatory conditions, and approximately 90 percent of each group underwent elective operations. The operative times were similar. Both groups had a similar number of abdominal operations before inclusion (mean = 1.2, both groups). Early morbidity rates were 17.8 percent for the Seprafilm group and 15.6 percent for the controls, with mortality rates of 0.8 percent and 0.0 percent, respectively. There were 12 intestinal obstructions in 12 patients in the Seprafilm group and 12 intestinal obstructions in 11 patients in the control group at a follow-up period of 65 months in the Seprafilm group and 81 months in the control group. Eight of the 12 intestinal obstructions in the Seprafilm group resolved with conservative management while only 5 of 12 in the control group responded without surgery. Thus the enterolysis rate was 1.5 percent in the Seprafilm group and 3.9 percent in the control group, demonstrating a trend in favor of Seprafilm. There were no statistically significant differences in the incidence of either overall or abdominopelvic septic complications between the Seprafilm (3.4 percent) and control (1.1 percent) groups. During short-term follow-up in this nonprospective, nonrandomized study, limited placement of Seprafilm did not significantly reduce the need for surgical enterolysis for intestinal obstruction or significantly adversely affect the morbidity rate. However, a long-term, prospective, randomized trial is underway to elucidate these issues.

Effect of HLA mismatching and antibody status on “homovital” aortic valve homograft performance

Background. Recipients of “homovital” aortic valve homografts are known to produce specific antibodies to human leukocyte antigen (HLA) determinants present on the cellular compartment of the valve tissue; however, the clinical significance of these antibodies is unknown. Data from 182 patients receiving homovital aortic valve homografts has been analyzed to determine the impact of HLA disparity and HLA antibody production on survival and function of the homograft. Methods. Human leukocyte antigen mismatch data were available for 127 patients (mean follow-up, 6.02 ± 0.26 years). Two patients were considered well matched for HLA A+B antigens (zero or one mismatch) compared with 125 poorly matched (two to four mismatches). Nine patients had a zero HLA-DR mismatch compared with 52 with one mismatch and 59 patients completely mismatched for DR antigens. Results. There was no significant association between the degree of HLA mismatch for either class I or class II antigens whether the loci were considered alone or in combination (ie, A, B, DR, AB, or ABDR mismatching) with markers of long-term valve function including patient mortality, reoperation, valve degeneration, valve stenosis, presence of regurgitation, and postoperative New York Heart Association class. One hundred thirty-six of 167 (82%) were found to have produced antibodies after operation (mean time after operation, 6.42 ± 0.58 years). In 61 cases both antibody specificity and donor HLA typing was available. In 92% of these, the antibodies were of the IgG subclass and were specific for the HLA class I molecules of the donor. The presence of HLA antibodies was associated with an increase in the frequency of mild valve stenosis (not significant) compared with those patients who did not develop HLA antibodies (antibody negative = 9.7%; panel reactive antibodies <50% = 29.1%; and panel reactive antibodies >50% = 22.2%; not significant). There was also an increased prevalence of valve degeneration associated with HLA antibodies. The actuarial freedom from valve degeneration for the 35 HLA antibody-negative patients was 100% at 1, 5, and 10 years compared with 100% at 1 year, 97% at 5 years, and 92% at 10 years for 55 patients with panel reactivity less than 50%, and 98% at 1 year, 94% at 5 years, and 88% at 10 years for the 77 patients who were highly sensitized (not significant). There was no correlation with other markers of long-term valve function. Conclusions. The influence of the immune response on valve function requires further studies involving large numbers of patients followed for a longer period of time. We believe prospective matching for HLA antigens is warranted to produce a well-matched cohort of patients for analysis and to reduce antibody sensitization, which would help to clarify this issue.