Interindividual differences in the clinical effectiveness of liraglutide in Type 2 diabetes: a real-world retrospective study conducted in Spain

AIMS

To study the response of clinical variables (HbA_1c , body weight, lipid profile and blood pressure) over 24 months of liraglutide treatment in a real-world clinical setting, and to describe the evolution of HbA_1c and body weight reduction in response to liraglutide treatment by employing generalized additive mixed models (GAMMs).

METHODS

We included people aged ≥ 18 years with Type 2 diabetes mellitus that initiated liraglutide treatment between November 2011 and May 2015. Demographic and clinical data were retrieved retrospectively over 24 months from electronic medical records with a median duration of observation of 7.0 (IQR 3.0-12.0) months.

RESULTS

Individuals that initiated liraglutide therapy were obese (BMI 39.1 kg/m² ), with inadequate HbA_1c (68 mmol/mol [8.4%]), blood pressure and lipid levels. Upon liraglutide treatment, HbA_1c , body weight, mean systolic and diastolic blood pressure, and lipid levels decreased gradually. GAMMs demonstrated that longer treatment with liraglutide was a predictor of improved HbA_1c response, whereas higher baseline HbA_1c , longer Type 2 diabetes duration and treatment with insulin were predictors of worse HbA_1c response. Higher baseline weight, longer treatment with liraglutide and the interaction between metformin and time were predictors of improved weight response.

CONCLUSIONS

In this real-world study, we showed the effectiveness of liraglutide in improving body weight, HbA_1c , mean systolic and diastolic blood pressure, and lipid levels. GAMMs indicated that baseline HbA_1c and weight, time of treatment with liraglutide, diabetes duration and the use of metformin or insulin are predictors of clinical response to liraglutide.

Optimum Sample Size to Estimate Mean Parasite Abundance in Fish Parasite Surveys

To reach ethically and scientifically valid mean abundance values in parasitological and epidemiological studies this paper considers analytic and simulation approaches for sample size determination. The sample size estimation was carried out by applying mathematical formula with predetermined precision level and parameter of the negative binomial distribution estimated from the empirical data. A simulation approach to optimum sample size determination aimed at the estimation of true value of the mean abundance and its confidence interval (CI) was based on the Bag of Little Bootstraps (BLB). The abundance of two species of monogenean parasites Ligophorus cephali and L. mediterraneus from Mugil cephalus across the Azov-Black Seas localities were subjected to the analysis. The dispersion pattern of both helminth species could be characterized as a highly aggregated distribution with the variance being substantially larger than the mean abundance. The holistic approach applied here offers a wide range of appropriate methods in searching for the optimum sample size and the understanding about the expected precision level of the mean. Given the superior performance of the BLB relative to formulae with its few assumptions, the bootstrap procedure is the preferred method. Two important assessments were performed in the present study: i) based on CIs width a reasonable precision level for the mean abundance in parasitological surveys of Ligophorus spp. could be chosen between 0.8 and 0.5 with 1.6 and 1x mean of the CIs width, and ii) the sample size equal 80 or more host individuals allows accurate and precise estimation of mean abundance. Meanwhile for the host sample size in range between 25 and 40 individuals, the median estimates showed minimal bias but the sampling distribution skewed to the low values; a sample size of 10 host individuals yielded to unreliable estimates.

Cone Beam Computed Tomography evaluation of palatal bone thickness for miniscrew placement in Down's syndrome

OBJECTIVES

To quantify palatal bone thickness (PBT) in Down's syndrome (DS) patients in order to identify the best areas for miniscrew placement.

DESIGN

The study group was formed of 40 DS patients (25 male and 15 female) with a mean age of 18.4±6.3 years (range, 9-40 years). A control group of 40 non-syndromic age- and sex-matched individuals was selected. Maxillary CBCT images were available for all participants. Coronal sections of the hard palate were selected at 4, 8, 16 and 24mm posterior to the distal wall of the incisive foramen. PBT measurements were performed at 20 selected points on these coronal sections at the midline and at 3 and 6mm to right and left of the suture.

RESULTS

Overall, PBT was similar in DS and controls and it was not affected by age or sex. In both groups PBT decreased progressively with increasing distance from the posterior wall of the nasopalatine foramen in an anteroposterior direction, except along the median palatal suture. PBT along the suture was lower in DS than in controls in all the paracoronal image planes (P=0.02, 0.007, 0.01 and 0.02 at 4mm, 8mm, 16mm and 24mm, respectively, from the incisive foramen). PBT at the most anterior paramedian locations was also lower in DS than in controls (P=0.02 and 0.03, respectively, 3mm to the right and left of midline).

CONCLUSIONS

In DS individuals, the most suitable area for miniscrew placement in terms of bone volume is the median palatal suture, irrespective of age or sex, as occurs in the general population, followed by the paramedian sites closest to the incisive foramen.

Prevalence of metabolic syndrome in Galicia (NW Spain) on four alternative definitions and association with insulin resistance

The present study evaluated the prevalence of the metabolic syndrome (MS) in a representative sample (no.=2860) of adults from the Spanish region of Galicia using the definitions of a) the World Health Organization; b) the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults; c) the European Group for Study of Insulin Resistance; and d) the International Diabetes Federation. In addition, we assess concordance among the different definitions, and the relationships of MS with insulin resistance (IR) as assessed by the homeostatic model assessment (HOMA-IR) index. Our results indicate a high prevalence of MS under all 4 definitions. MS prevalence was higher in men than women on all 4 definitions, and increased significantly with body mass index and age. IR was high among subjects with MS, and the HOMA index was a good discriminator of MS and non-MS on all 4 definitions, suggesting that HOMA index may be a useful predictive tool in clinical practice.

The action of pulse-modulated GSM radiation increases regional changes in brain activity and c-Fos expression in cortical and subcortical areas in a rat model of picrotoxin-induced seizure proneness

The action of the pulse-modulated GSM radiofrequency of mobile phones has been suggested as a physical phenomenon that might have biological effects on the mammalian central nervous system. In the present study, GSM-exposed picrotoxin-pretreated rats showed differences in clinical and EEG signs, and in c-Fos expression in the brain, with respect to picrotoxin-treated rats exposed to an equivalent dose of unmodulated radiation. Neither radiation treatment caused tissue heating, so thermal effects can be ruled out. The most marked effects of GSM radiation on c-Fos expression in picrotoxin-treated rats were observed in limbic structures, olfactory cortex areas and subcortical areas, the dentate gyrus, and the central lateral nucleus of the thalamic intralaminar nucleus group. Nonpicrotoxin-treated animals exposed to unmodulated radiation showed the highest levels of neuronal c-Fos expression in cortical areas. These results suggest a specific effect of the pulse modulation of GSM radiation on brain activity of a picrotoxin-induced seizure-proneness rat model and indicate that this mobile-phone-type radiation might induce regional changes in previous preexcitability conditions of neuronal activation.

Iodine nutrition in the adult population of Galicia (Spain)

OBJECTIVE

To identify the current state of iodine nutrition in the adult population of Galicia (Spain), which is considered iodine sufficient based on results from studies carried out on schoolchildren. Urinary iodine concentration (UIC) and its relationship with different socio-demographic variables were assessed.

DESIGN

A cross-sectional study was carried out on the population aged above 18 years in the Autonomous Community of Galicia (Spain) during 2004. The UICs were determined in an isolated urine sample using Dunn's colorimetric method. Iodine status was based on World Health Organization/International Council for the Control of Iodine Deficiency Disorders (WHO/ICCIDD) UIC.

MAIN OUTCOME

A total of 2877 urine samples were taken. Median UIC for the total Galician population was 75.6 microg/L. About 30% of the population showed a UIC below 50 microg/L. Educational level, place of residence (coast vs. inland), and consumption of iodized salt were independent variables associated with the iodine nutrition of the adult population of Galicia.

CONCLUSIONS

There is "mild" iodine deficiency (WHO) in the adult population of Galicia, which affects all the groups analyzed and which is particularly significant in the group of women of a fertile age. The data obtained on the state of iodine nutrition in school-age populations cannot be extended to the adult population.

[Factors determining the duration of temporary disability and return to work in a health district of Galicia]

OBJECTIVE

To determine the factors associated with the incidence and duration of temporary work incapacity (TWI) in a health district.

DESIGN

Descriptive and retrospective study.

SETTING

South health district of the province of Lugo, Spain.

PARTICIPANTS

A random sample of 1513 cases was selected among the total of episodes of TWI, during 3 years period.

MAIN MEASURES

The main factors analyzed are, on the one hand, the socio-demographic characteristics of the patient, his or her social security (SS) scheme, diagnosis that justifies the TWD, and the prescription date; and, on the other hand, the age, sex, specialised training, time in the post and years in practice of the physician who prescribes the TWI. The comparison of the means was carried out using variance analysis and the Kruskal-Wallis test. The relative effect of each variable on the probability of returning to the work was estimated through Cox regression models.

RESULTS

The mean duration of the episodes of TWI was of 74+/-103 days. The most frequent diagnoses were those of the bones-muscles and joints (BMAJ), injuries and poisonings (IAP), and respiratory diseases (RD). The probability of returning to work is reduced with the increase of the age, with agrarian and autonomous SS affiliates, with diagnoses of mental disease or diagnoses of the circulatory system, and in cases prescribed by older doctors or less time in the post.

CONCLUSIONS

The mean duration of the episodes of TWD is higher than that of other Spanish studies. The most influential factors in the return to work are the age of the patient, the SS scheme and the diagnosed illness.

Association between vitamin D receptor FokI. Polymorphism and serum parathyroid hormone level in patients with chronic renal failure

We investigated the relationship between vitamin D receptor (VDR) start codon polymorphism and serum levels of PTH, calcidiol, and calcium in 64 Spanish patients with chronic renal failure (CRF). An exon 2 fragment of the VDR gene was amplified by PCR, and cleaved with the restriction enzyme FokI. The alleles were identified according to the digestion pattern obtained as F (absence of restriction site) and f (presence of restriction site). Genotype frequencies in the patient population were 54.7% FF, 28.1% Ff and 17.2% ff, vs 46.7% FF, 43.3% Ff and 10% ff in a healthy control population. The difference between the two populations was statistically significant (p<0.01). Within the patient population, mean serum PTH level in the FF group was significantly higher (159.77+/-25.69 pg/ml) than in both the Ff and ff groups (106.67+/-19.07 and 77.55+/-15.85 pg/ml, respectively; p<0.05). However there were no significant differences in serum levels of calcidiol or calcium among genotypes. These results suggest that FokI polymorphisms of the VDR gene may determine parathyroid response in CRF patients.

Assessing relationships between health-related quality of life and adherence to antiretroviral therapy

OBJECTIVE

To investigate associations between health-related quality of life (HRQoL), as assessed using the multidimensional quality of life-HIV (MQOL-HIV) questionnaire, and adherence to antiretroviral treatment in HIV-infected subjects.

DESIGN

Multicentre cross-sectional study in three institutional tertiary hospitals in northwest Spain.

PATIENTS AND METHODS

The MQOL-HIV was completed by 235 HIV-infected adults undergoing antiretroviral treatment. Adherence to antiretroviral therapy was assessed by using patient's self-report. Information about sociodemographic characteristics and clinical variables was also collected.

RESULTS

Good adherence (> or = 95% of prescribed pills correctly taken) was reported by 131 patients (55.7%). Univariate analyses indicated that the sociodemographic and clinical variables associated with adherence were age, educational level, income, employment, home stability, transmission route, history of previous antiretroviral therapy, and number of prescribed pills/day. Subscales of MQOL-HIV associated with adherence were mental health, cognitive functioning, financial status, medical care, partner intimacy, and (in men only) sexual functioning. Stepwise logistic regression showed that good adherence was more frequent in patients aged > 40 years (odds ratio, OR: 2.50; 95% confidence interval, CI: 1.15-5.61) and in patients with high cognitive functioning (OR: 2.26; 95% CI: 1.19-4.30). Conversely, poor adherence was more frequent in patients without stable home (OR: 2.96; 95% CI: 1.39-6.32), in patients required to take 14 or more pills/day (OR: 2.17; 95% CI: 1.18-4.28), in patients with low financial status (OR: 3.42; 95% CI: 1.57-7.45), and in patients reporting low medical care (OR: 2.07; 95% CI: 1.07-3.98).

CONCLUSIONS

HRQoL dimensions, notably cognitive functioning, financial status and medical care, are closely associated with antiretroviral therapy adherence.

Application of nonparametric models for calculating odds ratios and their confidence intervals for continuous exposures

Calculating odds ratios and corresponding confidence intervals for exposures that have been measured using a continuous scale presents important limitations in the traditional practice of analytical epidemiology. Approximations based on linear models require making arbitrary assumptions about the shape of the relation curve or about its breakpoints. Categorical analyses generally have low statistical efficiency, and cutpoints for the categories are in most cases arbitrary and/or opportunistic. The use of logistic generalized additive models to calculate odds ratios does not require these assumptions and allows great flexibility and adequate statistical efficiency. Based on the asymptotic normality of the logarithm of the odds ratio, the authors propose the use of an approximate analytical expression for the corresponding covariance matrix, which will allow the construction of confidence intervals for odds ratios that can be interpreted as in the classical parametric context. The authors illustrate this procedure by examining the relation between glycemia and risk of postoperative infection, using data obtained from a cohort study of patients undergoing surgery in Santiago, Spain (January 1996--March 1997). The authors found that glycemia values below 75 mg/dl and above 130 mg/dl were associated with increased risk of postoperative infection.

Sulindac in familial adenomatous polyposis: evaluation by nuclear morphometry

OBJECTIVE

To find out if nuclear morphometry is a useful indicator of prognosis in patients with familial adenomatous polyposis (FAP) before and after treatment with sulindac.

DESIGN

Open study.

SETTING

Teaching hospital, Spain.

SUBJECTS

29 patients (17 women and 12 men) with FAP who had been treated by colectomy. There were two control groups: 17 people with healthy rectal mucosa and 10 patients with colorectal cancer.

INTERVENTIONS

The 29 patients with FAP were treated with sulindac 150 mg orally twice daily for 6 months.

MAIN OUTCOME MEASURES

Results of histological examination of biopsy specimens and nuclear morphometry.

RESULTS

Before treatment, all patients with FAP had nuclei of cells in the rectal mucosa that were intermediate in size between those in healthy mucosa (small nuclei) and those in cancer (large nuclei). After 6 months' treatment with sulindac the patients with FAP no longer had any polyps and the size of the nuclei was similar to those in healthy mucosa. Only 1 patient failed to respond, and in this patient one of the polyps subsequently became malignant.

CONCLUSIONS

Nuclear morphometry may be useful in identifying patients with FAP who are at high risk of malignant degeneration.

HEpiMA: software for the identification of heterogeneity in meta-analysis

Meta-analysis is a quantitative method available to epidemiologists, psychologists, social scientists and others who wish to produce a summary measure of the effect of exposure on disease, based on results from published studies along with a summary measure of uncertainty. The magnitude of the effect vary from study to study because of differences in the features of these studies (design, population, control of confounding variables etc.). From the various studies an estimator is formed by pooling the results found in each study in one summary measure. This summary (or pooled) measure is meaningful only if the magnitude of heterogeneity between study effects is small and can be explained by sampling variation. In this paper, we present HEpiMA, a new comprehensive and user-friendly software program for epidemiologic meta-analysis. HEpiMA has new features that are not available in other programs. The program carries out a complete study of heterogeneity of study effects with 11 hypothesis test results. In addition to model-based methods, the program also implements bootstrap methodology. New useful estimators of heterogeneity, Ri and CV(B), developed by the authors are given in the output. In addition to these unique features, the major advantage of this software is the option for direct entry of adjusted relative risk estimates of individual studies, the most common form of presentation of results in the epidemiologic literature. This program may also be useful for meta-analysts of clinical trials, in which the relative risk is the parameter of interest as it also allows the entry of crude data under the form of 2x2 tables.

Evaluation of old and new tests of heterogeneity in epidemiologic meta-analysis

The identification of heterogeneity in effects between studies is a key issue in meta-analyses of observational studies, since it is critical for determining whether it is appropriate to pool the individual results into one summary measure. The result of a hypothesis test is often used as the decision criterion. In this paper, the authors use a large simulation study patterned from the key features of five published epidemiologic meta-analyses to investigate the type I error and statistical power of five previously proposed asymptotic homogeneity tests, a parametric bootstrap version of each of the tests, and tau2-bootstrap, a test proposed by the authors. The results show that the asymptotic DerSimonian and Laird Q statistic and the bootstrap versions of the other tests give the correct type I error under the null hypothesis but that all of the tests considered have low statistical power, especially when the number of studies included in the meta-analysis is small (<20). From the point of view of validity, power, and computational ease, the Q statistic is clearly the best choice. The authors found that the performance of all of the tests considered did not depend appreciably upon the value of the pooled odds ratio, both for size and for power. Because tests for heterogeneity will often be underpowered, random effects models can be used routinely, and heterogeneity can be quantified by means of R(I), the proportion of the total variance of the pooled effect measure due to between-study variance, and CV(B), the between-study coefficient of variation.

Prognostic value of nuclear morphometry in colorectal cancer

PURPOSE

In many types of cancer, certain morphometric characteristic of tumor cells correlate with patient survival. Our observations suggested that the survival of patients with colorectal carcinomas is negatively correlated with tumor-cell nucleus size.

METHODS

We investigated relationships between postsurgery survival and nucleus morphometrics in 90 patients who had undergone resection for a colorectal tumor. The nucleus-size variables considered were maximum diameter, minimum diameter, perimeter, area, and form factor (means for 100 nuclei from each patient were used in all cases).

RESULTS

Our results confirmed that patients with large maximum nucleus diameter (where large = greater than the first quartile) have significantly worse survival than patients with smaller maximum nucleus diameter (mean survival, 28 vs. 43 months). Similar results were obtained for the other nucleus-size variables. Stepwise Cox regression analysis was then performed, with postsurgery survival time as the dependent variable and the following candidate independent variables: age, gender, Dukes class, degree of histologic differentiation, the various nucleus-size variables, and relative frequencies of different nucleus shapes (spherical, oval, cylindrical, fusiform, and irregular). The variables selected for the prognostic model were Dukes class, relative frequency of irregular nuclei, and maximum nucleus diameter.

CONCLUSIONS

These findings indicated that nucleus size and shape are useful predictors of survival. Even if Dukes class is known, consideration of nucleus size and shape significantly improves prediction of survival.