36 research outputs found
Regression methods for investigating risk factors of chronic kidney disease outcomes: the state of the art
Smoking status and common carotid artery intima-medial thickness among middle-aged men and women based on ultrasound measurement: a cohort study
BACKGROUND: Cigarette smoking is an established causal factor for atherosclerosis. However, the smoking effect on different echogenic components of carotid arterial wall measured by ultrasound is not well elucidated. METHODS: Middle-aged men and women who had IMT measurement â„ 0.7 mm at baseline and follow-up were included (N = 413, age 40â60 years at baseline in 1995). Intima-media thickness of common carotid artery (CCA-IMT) and its components (echogenic and echolucent layers) were measured at baseline and in the follow-up examination 3 years later. IMT and its components were compared across current, former and never smokers. Individual growth models were used to examine how smoking status was related to the baseline and progression of overall IMT and IMT components. RESULTS: For both men and women, current smoking was associated with thicker echogenic layer than never smokers; former smokers exhibited thinner echogenic layer than current smokers after adjustment for cigarette pack-years. Among women, current smoking was also associated with a thinned echolucent layer that resulted in a non-significant overall association of current smoking with IMT for women. CONCLUSION: Cigarette smoking is associated with carotid artery morphological changes and the association is sex-dependent. The atherogenic effect of smoking appears to be partly reversible among former smokers. IMT measurement alone may not be adequate to detect carotid atherosclerosis associated with cigarette smoking among middle-age women
The risk of lung cancer related to dietary intake of flavonoids
It has been hypothesized that flavonoids in foods and beverages may reduce cancer risk through
antioxidation, inhibition of inflammation, and other antimutagenic and antiproliferative
properties. We examined associations between intake of five flavonoid subclasses
(anthocyanidins, flavan-3-ols, flavones, flavonols, flavanones) and lung cancer risk in a
population-based case-control study in Montreal, Canada (1,061 cases and 1,425 controls).
Flavonoid intake was estimated from a food frequency questionnaire that assessed diet two years
prior to diagnosis (cases) or interview (controls). Odds ratios (ORs) and 95% confidence
intervals (CIs) were estimated using unconditional logistic regression. Overall, total flavonoid
intake was not associated with lung cancer risk, the effect being similar regardless of sex and
smoking level. However, low flavonoid intake from food, but not from beverages, was
associated with an increased risk. The adjusted ORs (95% CIs) comparing the highest versus the
lowest quartiles of intake were 0.63 (0.47-0.85) for total flavonoids, 0.82 (0.61-1.11) for
anthocyanidins, 0.67 (0.50-0.90) for flavan-3-ols, 0.68 (0.50-0.93) for flavones, 0.62 (0.45-0.84)
for flavonols, and 0.70 (0.53-0.94) for flavanones. An inverse association with total flavone and
flavanone intake was observed for squamous cell carcinoma but not adenocarcinoma. In
conclusion, low flavonoid intake from food may increase lung cancer risk
PLoS One
Quantifying the association between lifetime exposures and the risk of developing a chronic disease is a recurrent challenge in epidemiology. Individual exposure trajectories are often heterogeneous and studying their associations with the risk of disease is not straightforward. We propose to use a latent class mixed model (LCMM) to identify profiles (latent classes) of exposure trajectories and estimate their association with the risk of disease. The methodology is applied to study the association between lifetime trajectories of smoking or occupational exposure to asbestos and the risk of lung cancer in males of the ICARE population-based case-control study. Asbestos exposure was assessed using a job exposure matrix. The classes of exposure trajectories were identified using two separate LCMM for smoking and asbestos, and the association between the identified classes and the risk of lung cancer was estimated in a second stage using weighted logistic regression and all subjects. A total of 2026/2610 cases/controls had complete information on both smoking and asbestos exposure, including 1938/1837 cases/controls ever smokers, and 1417/1520 cases/controls ever exposed to asbestos. The LCMM identified four latent classes of smoking trajectories which had different risks of lung cancer, all much stronger than never smokers. The most frequent class had moderate constant intensity over lifetime while the three others had either long-term, distant or recent high intensity. The latter had the strongest risk of lung cancer. We identified five classes of asbestos exposure trajectories which all had higher risk of lung cancer compared to men never occupationally exposed to asbestos, whatever the dose and the timing of exposure. The proposed approach opens new perspectives for the analyses of dose-time-response relationships between protracted exposures and the risk of developing a chronic disease, by providing a complete picture of exposure history in terms of intensity, duration, and timing of exposure
Construction of quality of life change patterns: example in oncology in a phase III therapeutic trial (FFCD 0307)
Should We Use Standard Survival Models or the Illness-Death Model for Interval-Censored Data to Investigate Risk Factors of Chronic Kidney Disease Progression?
Prog Urol
Objectifs: La prĂ©valence de l'obĂ©sitĂ© n'a cessĂ© d'augmenter ces 20 derniĂšres annĂ©es dans la population gĂ©nĂ©rale et parmi les patients receveurs de transplants rĂ©naux. Dans l'esprit chirurgical, l'obĂ©sitĂ© est associĂ©e Ă une augmentation des difficultĂ©s chirurgicales. L'objectif de cette Ă©tude Ă©tait dâĂ©valuer l'impact de l'IMC sur les complications pĂ©riopĂ©ratoires. MĂ©thodes: Toutes les transplantations rĂ©nales rĂ©alisĂ©es chez l'adulte dans notre centre de 2006 Ă 2011 ont Ă©tĂ© analysĂ©es. Les donnĂ©es concernant les caractĂ©ristiques des patients, la procĂ©dure chirurgicale, les complications per- et postopĂ©ratoires ainsi que la fonction rĂ©nale ont Ă©tĂ© collectĂ©es. Les patients on Ă©tĂ© repartis en 4 groupes: sous-poids (BMI < 18,5 kg/m2), poids normal (18,5 kg/m2 †BMI < 25 kg/m2), surpoids (25 kg/m2 †BMI < 30 kg/m2) et obĂ©sitĂ© (BMI â„ 30 kg/m2). Nous avons Ă©galement Ă©tudiĂ© l'impact de l'IMC sur les complications en tant que variable continue afin d'identifier de potentielles valeurs seuils. RĂ©sultats: Parmi 694 patients inclus, 52 % avait un IMC normal, 7 %, 31 % et 9 % Ă©taient respectivement en sous-poids, surpoids et obĂšses. En analyse multivariĂ©e, le surpoids Ă©tait associĂ© Ă une augmentation de la durĂ©e opĂ©ratoire comparĂ© au patients de poids normal (diffĂ©rence moyenne estimĂ©e Ă 10,4 min, 95 % intervalle de confiance (IC) [4,0; 16,9]) et l'obĂ©sitĂ© Ă©tait associĂ©e Ă une augmentation du risque dâĂ©ventration (odds ratio 3,1, 95 %CI [1,3; 7,3] comparĂ© aux patients de poids normal). En considĂ©rant l'IMC en tant que variable continue le risque dâĂ©ventration augmentait significativement au-delĂ d'un IMC Ă 26 kg/m2, de pertes sanguines et de stĂ©nose urĂ©tĂ©rale au-delĂ d'un IMC Ă 32 kg/m2 et d'hĂ©matome de paroi au-delĂ d'un IMC Ă 34 kg/m2. Conclusions: Nous avons trouvĂ© des seuils d'IMC au-delĂ desquels les pertes sanguines, le risque dâĂ©ventration, de stĂ©nose urĂ©tĂ©rale et d'hĂ©matome de paroi augmentent significativement. Niveau de preuve: 3. © 2020 Elsevier Masson SASObjectives: Obesity prevalence has increased over the past 20 years in the general population and among kidney transplant recipients. General surgical belief is that obesity increases surgical difficulty. The aim of this study was to assess the impact of Body Mass Index (BMI) on perioperative complications. Methods: All kidney transplantations performed in adults in our centre from 2006 to 2011 were analysed. Data on patientsâ characteristics, surgical protocol, intra and postoperative complications and renal function were collected. Patients were divided into 4 groups as follows: underweight (BMI < 18.5 kg/m2), normal weight (18.5 kg/m2 †BMI < 25 kg/m2), overweight (25 kg/m2 †BMI < 30 kg/m2) and obese (BMI â„ 30 kg/m2). We also studied the impact of BMI on complications using it as a continuous variable to identify potential threshold values. Results: Among 694 patients included, 52% had normal BMI, 7%, 31% and 9% were underweight, overweight and obese, respectively. In multivariate analysis, overweight was significantly associated with longer operative time compared to normal-weight patients (estimated mean difference of 10,4 min, 95% confidence interval (CI) [4.0; 16.9]) and obesity was associated with an increased risk of wound dehiscence (odds ratio 3.1, 95% CI [1.3; 7.3] compared with normal-weight patients). Considering BMI as a continuous variable, the risk of parietal dehiscence significantly increased beyond a BMI of 26 kg/m2, intraoperative blood loss and the risk of ureteral stenosis beyond 32 kg/m2 and the risk of abdominal wall hematoma beyond a BMI of 34 kg/m2. Conclusions: We found BMI thresholds above which intraoperative blood loss and the risk of parietal dehiscence, ureteral stenosis, and parietal hematoma significantly increased. Level of evidence: 3. © 2020 Elsevier Masson SA
Estimating time-varying exposure-outcome associations using case-control data: logistic and case-cohort analyses
Risk Factors of Early Kidney Graft Transplantectomy
BACKGROUND: Kidney allograft explant in the first month after transplant is a major concern for medicosurgical teams specialized in kidney transplantation and unacceptable graft loss in the current shortage. The aim of our study was to evaluate the risk factors of early kidney graft explant. METHODS: We retrospectively analyzed all adult kidney transplantations performed at our center from January 2006 to December 2011. Recipient, donor, and transplant characteristics were collected, as well as operating data and early postoperative complications. Univariate and multivariate logistic regression models were used to determine risk factors of early renal allograft explant. RESULTS: From a total of 707 kidney transplantations, 28 transplantectomies were performed in the first month following transplantation (3.96%). The average delay in days +/- SD was 7.6 +/- 10. Eighty-six percent of transplantectomies were due to vascular complications. In multivariate analysis, obesity (odds ratio [OR] = 9.6; 95% confidence interval [CI], 1.63-56.5; P = .0007), range of transplantation (OR = 36.89; 95%CI, 5.5-245; P = .0006), intraoperative complications (OR = 3.99; 95%CI, 1.22-13; P = .026), and early postoperative vascular complications (OR = 85.15; 95%CI, 23.6-306; P < .0001) were independent risk factors. Neither donors nor graft characteristics were significant. CONCLUSIONS: Early renal graft transplantectomies are rare but account for 50% of renal graft loss in the first year. Because obesity, perioperative complications, and early vascular complications are independent factors associated with early transplantectomies, their prevention should be based on meticulous surgery during organ procurement, implantation of the kidney, and on the rehabilitation of future recipients