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Jokin de Irala

Publications and source records attributed to Jokin de Irala.

14 recordsLinked to original sources
PubMed2006

Predictors of follow-up and assessment of selection bias from dropouts using inverse probability weighting in a cohort of university graduates.

Dropouts in cohort studies can introduce selection bias. In this paper, we aimed (i) to assess predictors of retention in a cohort study (the SUN Project) where participants are followed-up through biennial mailed questionnaires, and (ii) to evaluate whether differential follow-up introduced selection bias in rate ratio (RR) estimates. The SUN Study recruited 9907 participants from December 1999 to January 2002. Among them, 8647 (87%) participants answered the 2-year follow-up questionnaire. The presence of missing information in key variables at baseline, being younger, smoker, a marital status different of married, being obese/overweight and a history of motor vehicle injury were associated with being lost to follow-up, while a self-reported history of cardiovascular disease predicted a higher retention proportion. To assess whether differential follow-up affected RR estimates, we studied the association between body mass index and the risk of hypertension, using inverse probability weighting (IPW) to adjust for confounding and selection bias. Obese individuals had a higher crude rate of hypertension compared with normoweight participants (RR=6.4, 95% confidence interval (CI): 3.9-10.5). Adjustment for confounding using IPW attenuated the risk of hypertension associated to obesity (RR=2.4, 95% CI: 1.1-5.3). Additional adjustment for selection bias did not modify the estimations. In conclusion, we show that the follow-up through mailed questionnaires of a geographically disperse cohort in Spain is possible. Furthermore, we show that despite existing differences between retained or lost to follow-up participants this may not necessarily have an important impact on the RR estimates of hypertension associated to obesity.

Adult↗
PubMed2005

Causal relationship between cannabis use and psychotic symptoms or depression. Should we wait and see? A public health perspective.

The aim of this paper is to update and critically analyze the public health relevance of available evidence about the causal relationship between cannabis use and psychosis or depression. There are conflicting views about this causal relationship. Two systematic reviews of existing evidence assessed this association and were published in 2004, but they came to different conclusions. From a public health perspective a thorough discussion is warranted before attributing any observed effect to potential biases. First, the impact of residual confounding in this causal relationship is discussed. We consider that the attenuation of estimates after controlling for confounding factors cannot be interpreted as evidence to support the claim that residual confounding fully explains this link. Secondly, taking into account the results of recent studies, the time-sequence and dose-response criteria of causality are discussed. The fact that unreported or subclinical psychological problems might have preceded and precipitated cannabis use is a very unlikely explanation when the cannabis-psychosis outcome link is assessed from different longitudinal studies. And finally, available evidence is interpreted with a broad view of public health and by taking into account the precautionary principle. We therefore provide reasons to support the case that stronger preventive actions against cannabis are still required in order to avoid the potential increased incidence of psychosocial health problems in the future.

Depression↗
PubMed2004

Fruit and vegetable consumption is inversely associated with blood pressure in a Mediterranean population with a high vegetable-fat intake: the Seguimiento Universidad de Navarra (SUN) Study.

There is evidence that a diet rich in fruit and vegetables reduces blood pressure (BP). Characteristically, the Mediterranean diet is rich in plant-derived foods and also in fat, but studies conducted in Mediterranean countries to relate diet to BP are scarce. We studied the association between fruit and vegetable consumption and BP in a cross-sectional analysis of 4393 participants in the Seguimiento Universidad de Navarra (SUN) Study, an ongoing dynamic cohort study in Spain. Diet was measured using a food-frequency questionnaire previously validated in Spain. Fat represented more than 37 % total energy intake. Subjects were considered to have undiagnosed hypertension if they reported systolic BP > or = 140 mmHg or diastolic BP > or = 90 mmHg, and not a medical diagnosis of hypertension. The adjusted prevalence odds ratio of undiagnosed hypertension (upper v. lowest quintile) was 0.58 (95 % CI 0.36, 0.91; P for trend 0.01) for vegetable consumption and 0.68 (95 % CI 0.43, 1.09; P for trend 0.10) for fruit consumption. Comparing those in the highest quintile of both fruit and vegetable consumption with those in the lowest quintile of both food groups, the prevalence odds ratio was 0.23 (95 % CI 0.10, 0.55; P = 0.001), after adjusting for risk factors for hypertension and other dietary exposures. In a Mediterranean population with an elevated fat consumption, a high fruit and vegetable intake is inversely associated with BP levels.

Adult↗
PubMed2003

[Smoking cessation and risk of myocardial reinfarction in coronary patients: a nested case-control study].

INTRODUCTION AND OBJECTIVES: Smoking cessation reduces mortality in coronary patients. The aim of this study was to estimate association measures between the risk of occurrence of fatal or non-fatal reinfarction in patients who either continue to smoke or stop after a first infarction and are treated with secondary prevention measures. PATIENTS AND METHOD: The study was a case-control (1:1) design nested in a cohort of 985 coronary patients under the age of 76 years who were not treated with invasive procedures and survived more than 6 months after the first acute myocardial infarction. Cases were all patients who suffered reinfarction (n = 137) between 1997 and 2000. A control patient was matched with each case by gender, age, hospital, interviewer, and the secondary prevention timeframe. RESULTS: Patients who smoke after the first acute myocardial infarction had an Odds ratio (OR) of 2.83 (95% CI, 1.47-5.47) for a new acute myocardial infarction. Adjustment for lifestyle, drug treatment, and risk factors (family history of coronary disease, high blood pressure, hypercholesterolemia, and diabetes mellitus) did not change the OR (2.80 [95% CI, 1.35-5.80]). Patients who quit smoking had an adjusted OR of 0.90 (95% CI, 0.47-1.71) compared with non-smokers before the first acute myocardial infarction. Continued smoking had an adjusted OR of 2.90 (95% CI, 1.35-6.20) compared to quitting after the first acute myocardial infarction. CONCLUSION: The risk of acute myocardial infarctions is three times higher in patients who continue to smoke after an acute coronary event compared with patients who quit. The risk of reinfarction in patients who stop smoking is similar to the risk of non-smokers before the first infarction.

Aged↗
PubMed2002

Involvement of leptin in the association between percentage of body fat and cardiovascular risk factors.

OBJECTIVES: Recent epidemiologic studies have shown that obesity is associated with elevated blood concentrations of prothrombotic-proinflammatory factors and markers of endothelial dysfunction such as fibrinogen, C-reactive protein (CRP), von Willebrand factor (vWF), and homocysteine. We have assessed whether these markers are associated with percentage of body fat (BF), insulin sensitivity as well as with leptin concentrations. DESIGN AND METHODS: Twenty-five men aged 49.6 +/- 12.7 yr (mean +/- SD) underwent whole-body air displacement plethysmography (Bod-Pod(R)) for estimating BF. Blood analyses for leptin and several other metabolic and cardiovascular markers were carried out. RESULTS: Obese subjects had higher levels as compared to controls of BF (37.5 +/- 5.1 vs. 26.0 +/- 6.6, p < 0.01), fibrinogen (3.30 +/- 0.43 vs. 2.67 +/- 0.11, p < 0.01), vWF (136.4 +/- 50.4% vs. 81.6 +/- 12.6%, p < 0.05), and leptin (17.6 +/- 8.7 vs. 6.2 +/- 3.3, p < 0.01), lower concentrations of HDL-cholesterol (1.09 +/- 0.20 vs. 1.51 +/- 0.10, p < 0.001) and lower QUICKI (1/[log(Ins(0)) + log(Glu(0))]) (0.31 +/- 0.03 vs. 0.34 +/- 0.02, p < 0.05). No significant changes were observed in CRP (5.7 +/- 3.4 vs. 3.8 +/- 1.6, p = 0.327) and homocysteine (9.4 +/- 4.2 vs. 8.3 +/- 0.9, p = 0.749). A positive correlation was observed between BF and fibrinogen (r = 0.67, p = 0.0003). Plasma leptin concentrations were correlated with fibrinogen (r = 0.71, p = 0.0001) and CRP (r = 0.43, p = 0.044). After adjustment for BF leptin emerged as a significant predictor of fibrinogen (beta = 0.47, p = 0.023; R(2) = 0.59, p < 0.001). QUICKI was positively correlated with HDL-cholesterol (r = 0.59, p = 0.010) and negatively with fibrinogen (r = -0.53, p = 0.025), CRP (r = -0.52, p = 0.028) and vWF (r = -0.56, p = 0.013). CONCLUSIONS: Increased BF and impaired insulin sensitivity are associated with increased concentrations of cardiovascular risk factors. Leptin seems to be involved in this elevation and emerges as a predictor of circulating fibrinogen concentrations.

Adipose Tissue↗
PubMed2002

Combined irinotecan, oxaliplatin and 5-fluorouracil in patients with advanced colorectal cancer. a feasibility pilot study.

OBJECTIVES: To evaluate the feasibility and a possible activity range of combination irinotecan (CPT-11), oxaliplatin, and 5-FU in advanced colorectal cancer (ACC). PATIENTS AND METHODS: A total of 53 patients (51% chemoresistant) were treated. Twenty-eight received monthly intravenous oxaliplatin (120 mg/m2) and CPT-11 (250 mg/m2) on day 1 and a course of 5-FU; these constituted the IRI250 group. Twenty-five received monthly intravenous oxaliplatin (120 mg/m2), CPT-11 (300 mg/m2) on day 1, and a course of 5-FU (IRI300 group). 5-FU administration was carried out as follows. Those with predominant hepatic disease (n = 32) received an intra-arterial infusion of 5-FU (2,500 mg/day on days 1-4); these were the IA-FU group. The remaining 21 patients received intravenous 5-FU (2,600 mg/m2 plus leucovorin 500 mg/m2 on days 1 and 15); these constituted the IV-FUFOL group. RESULTS: Intention-to-treat response rate was 54.7% (4 CR, 7.5%). Twelve patients (22.5%) had stable disease; only 4 (7.5%) progressed. Median progression-free and overall survivals were 10 and 18 months, respectively. One-year progression-free and overall survival rates were 44.3 and 67.4%, respectively. Grade 3-4 toxicities included diarrhea (45.3% of patients), neutropenia (52.8%), mucositis (13.2%), and emesis (11.3%). There were 3 treatment-related deaths (5.7%), all in the IA-FU/IRI300 subgroup. Severe adverse effects requiring chemotherapy dose adjustment were observed in 67.9% of the patients, with odds ratios 9.04-fold higher in the IA-FU/IRI300 group (95% CI: 1.07-76.20) and 0.23-fold lower in the IV-FUFOL/IRI250 group (95% CI: 0.05-0.97). CONCLUSION: This combination seems to have substantial activity in ACC. Overall toxicity was unacceptable in the IA-FU and IRI300 groups, with diarrhea and cytopenia constituting the dose-limiting side effects. Tolerance and efficacy profiles achieved with IV oxaliplatin (120 mg/m2 day 1), IV CPT-11 (250 mg/m2 day 1) and IV 5-FU 2.6 g/m2 with IV leucovorin (500 mg/m2 days 1 and 15) was favorable and deserves further investigation.

Adenocarcinoma↗
PubMed2002

Irinotecan, oxaliplatin, and 5-fluorouracil/leucovorin combination chemotherapy in advanced colorectal carcinoma: a phase II study.

The purpose of this study was to evaluate the efficacy and tolerance of a combination of irinotecan, oxaliplatin, and 5-fluorouracil (5-FU)/leucovorin in advanced colorectal cancer (ACC). Twenty-six consecutive patients with ACC and an Eastern Cooperative Oncology Group performance status of 0-2 were treated with a combination of oxaliplatin (120 mg/m2 intravenously [i.v.] for 2 hours) on day 1, irinotecan (250 mg/m2 i.v. for 90 minutes) on day 1, and 5-FU (2600 mg/m2 plus leucovorin 500 mg/m2 i.v. in a 24-hour infusion) on day 1 and 15, every 4 weeks. Five of the patients (19.2%) had shown previous chemoresistance. One hundred sixty-two cycles were administered (median, 6; range, 3-13 cycles). All patients were evaluated for toxicity; 23 were evaluable for response. According to intention-to-treat, the overall response rate was 69.2% (18 patients; 95% CI: 48.2%-85.7%), including 3 complete remissions (11.5%). Four additional patients (15.3%) had stable disease, and only 1 (3.8%) progressed. Major toxicities were neutropenia and diarrhea. Grade 3 neutropenia occurred in 9 patients (34.6%), and grade 4 occurred in 1 patient (3.8%). Grade 3 diarrhea occurred in 8 patients (30.7%) and grade 4 in 1 patient (3.8%). Other toxicities were mild. After a median follow-up of 15.5 months, the median progression-free survival was 14 months. Seventeen patients (65.4%) are still alive, and the median overall survival has not been reached yet. This combination of irinotecan, oxaliplatin, and 5-FU/leucovorin is fairly well tolerated and shows promising activity in ACC. This treatment merits further comparison with other combination regimens.

Adenocarcinoma↗