A short note on the BMI and on secular changes in BMI

Human size changes over time with worldwide secular trends in height, weight, and body mass index (BMI). There is general agreement to relate the state of nutrition to height and weight, and to ratios of weight-to-height. The BMI is a ratio. It is commonly used to classify underweight, overweight and obesity in adults. Yet, the BMI is inappropriate to provide any immediate information on body composition. It is accepted that the BMI is “a simple index to classify underweight, overweight and obesity in adults”. It is stated that “policies, programmes and investments need to be “nutrition-sensitive”, which means they must have positive impacts on nutrition”. It is also stated that “a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions“. But these statements are neither warranted by arithmetic considerations, nor by historic evidence. Measuring the BMI is an appropriate screening tool for detecting an unusual weight-to-height ratio, but the BMI is an inappropriate tool for estimating body composition, or suggesting medical and health policy decisions.

The relation between head circumference and mid pelvic circumference: A simple index for cephalo-pelvic disproportion evaluation

Introduction: Cephalo-pelvic-disproportion (CPD) is one of the most common obstetric complications. Since CPD is the disproportion between the fetal head and maternal bony pelvis, evaluation of the head-circumference (HC) relative to maternal bony pelvis may be a useful adjunct to pre-labor CPD evaluation. The aim of the present study was a proof-of-concept evaluation of the ratio between HC to pelvic circumference (PC) as a predictor of CPD. Methods: Of 11,822 deliveries, 104 cases that underwent an abdomino-pelvic CT for any medical indication and who underwent normal vaginal deliveries (NVD) (n=84) or cesarean deliveries (CD) due to CPD (n=20) were included retrospectively. Maternal pelvis dimensions were reconstructed and neonatal HC, as a proxy for fetal HC, were measured. The correlation between cases of CPD and Cephalo-Pelvic Circumference Index (CPCI), which represents the ratio between the HC and PC in percent (HC/PC *100) was evaluated. Results: The mid-pelvis cephalo-pelvic circumference index (MP-CPCI) was larger in CD groups as compared to the NVD group: 103±11 vs. 97±8% respectively (p=0.0003). In logistic regression analysis, the MP-CPCI was found to be independently associated with CD due to CPD: each 1% increase in MP-CPCI increased the likelihood of CD for CPD by 11% (aOR 1.11, CI 95% 1.03-1.19, p=0.004). The adjusted odds ratio for CD due to CPD increased incrementally as the MP-CPCI increased, from 3.56 (95%CI, 1.01-12.6) at MP-CPCI of 100, to 5.6 (95%CI, 1.63-19.45) at 105, 21.44 (95%CI, 3.05-150.84) at 110, and 28.88 (95%CI, 2.3-362.27) at MP-CPCI of 115 Conclusions: The MP-CPCI, representing the relative dimensions of the fetal HC and maternal PC, is a simple tool that can potentially distinguish between parturients at lower and higher risk of CPD. Prospective randomized studies are required to evaluate the feasibility of prenatal pelvimetry and MP-CPCI to predict the risk of CPD during labor.

Venous tortuosity as a novel biomarker of rupture risk in arteriovenous malformations: ARI score

BackgroundRisk of rupture in arteriovenous malformations (AVMs) varies considerably among series. Hemodynamic factors, especially within the venous side of the circuit, seem to be responsible but are not yet well defined. We analyzed tortuosity in the draining vein as a potential new marker of rupture in AVMs, and propose a simple index to predict AVM bleeding.MethodsA retrospective analysis of the venous angioarchitecture of brain AVMs was carried out at our center from 2013 to 2021, with special attention to venous tortuosity. After univariate analysis, the features of interest were combined to construct several predictive models using multivariate logistic regression. The best model proposed was the new AVM rupture index (ARI), which was then validated in an independent cohort.Results68 AVMs were included in the first step and 32 in the validation cohort. Venous tortuosity, expressed as at least one curve >180°, was a significant predictor of rupture (p=0.023). The proposed bleeding index consisted of: venous tortuosity (any curve of >180°), single draining vein, and paraventricular/infratentorial location. It seems to be a robust evaluation tool, with an area under the receiver operating characteristic (AUROC) curve of 0.806 (95% CI 0.714 to 0.899), consistently replicated in the independent sample (AUROC 0.759 (95% CI 0.607 to 0.911)), and with an inter-rater kappa coefficient of 0.81 .ConclusionsVenous tortuosity may serve as a predictor of bleeding in AVMs that warrants further investigation. This likely new marker was one of the three elements of the proposed ARI. ARI outperformed the predictive accuracy of previous scores, and remained consistent in an independent cohort.

Roaming Dogs in Ushuaia City, Tierra Del Fuego, Argentina. How Many and Why

Free roaming dogs (FRD) in cities represent an increasing problem. Authorities need numbers of FRDs to evaluate policies implemented and to monitor the dog population. We estimated the number of FRD in Ushuaia city, Argentina, using a photographic capture-recapture methodology. We estimated an abundance index, the power to detect changes in the index, and modeled factors that may explain the spatial distribution of FRD and their welfare status. During three surveys, covering 72 transects along streets (9.9% of the street layout of Ushuaia), we recorded 539 different FRDs. A model with individual heterogeneity in capture-recapture probability gave 12,797 FRDs (95% CI 10,979 − 15,323), reflecting a dog:human relation of 1:6, higher than the relation recommended by the WHO. The abundance index was similar between surveys (8.13 ± 1.36, 8.38 ± 1.46 and 9.55 ± 1.28 dogs/km). The difference needed to detect changes in the index is about twice the standard error of estimates. The best model explaining dogs’ abundance included only geographical location, although two neighbourhoods with 9 transects stand out with 181 different FRDs identified. Together with the good overall dogs’ welfare status, modeling suggests that the behavior of owners is the main driver for the presence of FRDs. We recommend the use of photographic capture-recapture methodologies instead of simple index estimation, due to the small additional effort required and the improved accuracy and precision obtained. We also recommend a permanent systematic design for future surveys, increase the number of survey occasions, and improve the survey process.

Drought monitoring over India through Normalized Difference Vegetation Index (NDVI)

Normalized Difference Vegetation Index (NDVI) is a simple index to monitor the state of vegetation (stressed/unstressed) which can be derived from satellite data. Hence an attempt is made to find out the vegetation responses to rainfall through NDVI over the study area. Applicability of NDVI in drought monitoring is discussed using the NDVI and rainfall data for the period 1982-2003. The anomaly of NDVI is compared with the percentage departure of rainfall of corresponding years. Results showed a significant relation between the NDVI with the percentage departure of rainfall. The time series plots of averaged NDVI and seasonal rainfall (June-September) are done for NW India (21° N - 31° N, 68° E - 78° E), Central India (22° N - 27° N, 70° E - 77° E) and Peninsular India (16° N - 21° N, 74° E - 79° E) over the period 1982-2003 to analyze changes in vegetation pattern of India during the last two decades. Results indicated a clear linear relationship over NW and Central India. NDVI anomalies and the corresponding cumulative rainfall showed significantly linear correlation of 0.69 over NW India and 0.57 over Central India significant at 1% level but the correlation is found to be insignificant over Peninsular India which was only 0.04. Trend analysis of averaged NDVI over India showed that during last two decades the vegetation status had quite improved over the dry farming tracts of India.

Location, location, location -- Considering relative catchment location to understand subsurface losses

The analysis of large samples of hydrologic catchments is regularly used to gain understanding of hydrologic variability and controlling processes. Several studies have pointed towards the problem that available catchment descriptors (such as mean topographic slope or average subsurface properties) are insufficient to capture hydrologically relevant properties. Here, we test the assumption that catchment location, i.e. the relative properties of catchments in relation to their surrounding neighbours, can provide additional information to reduce this problem. We test this idea in the context of Great Britain for a widely discussed problem, that of catchment water balance errors due to subsurface losses. We test three hypotheses while considering different locational aspects (1) location to coast, (2) location next a relevant neighbour and (3) location within the drainage basin, utilizing only basic and widely available geological and topographical information. We find that subsurface losses from catchments with a highly permeable geology connection to the coast are in order of 20% water balance error. We define a simple topographic-geologic index that is able to partially explain water balance issues between neighbours of highly permeable catchments. The results imply that location, geology and topography combine to define the differences of water balances of UK catchments compared to what we would expect from their climatic setting alone. The simple index defined here can easily be derived globally and tested regarding its wider applicability.

Correlation of the Neutrophil Lymphocyte Ratio with Malignancy Status in Thyroid Nodule

Background: Thyroid nodules are very common, found in more than 50% of patients when using ultrasonography. While the prevalence of thyroid nodules in the population is increasing, only 5% to 10% harbor malignant disease. Still, there is a pressing need to correctly identify the nature of thyroid nodules, because thyroid cancer is the most common endocrine malignancy and often presents in thyroid nodules. Inflammation plays a critical role in many aspects of cancer, including tumor development, progression, clinical presentations, and prognosis. The neutrophil/ lymphocyte ratio (NLR) is a simple index of systemic inflammatory response1,2. The aim of this study is to determine whether there is a relationship between the neutrophil/lymphocyte ratio with malignancy status of thyroid nodules. Methods: One hundred two cases of benign and malignant thyroid nodule were analyzed retrospectively. We evaluated neutrophil lymphocyte ratio with result post-operative pathological anatomy. Complete blood counts with differential counts were taken before operation. NLR was calculated by dividing preoperative neutrophil count with lymphocyte count. Sample were categorized into low grade (NLR < 1,91) and high grade (NLR ≥ 1,92). Results: There was statistically significant difference of neutrophil-lymphocyte ratio between benign thyroid nodule and malignant thyroid nodule (p=0,001). Conclusion: NLR is easily accessible tests that can be automatically calculated from complete blood count without additional cost in differentiation of malignant thyroid nodule from benign nodule in the preoperative period. Keywords: Thyroid nodule; neutrophil lymphocyte ratio; malignancy.