Estimating disease prevalence using census data

Lipedema prevalence and risk factors in Brazil

Background

Lipedema is characterized as an abnormal deposition of fat in the buttocks and legs bilaterally that may be accompanied by swelling, pain, and tenderness. It is still often confused with more frequent conditions such as obesity and lymphedema. The estimated prevalence in Europe varies between 0.06% and 39%.

Objectives

To evaluate the prevalence of lipedema and identify health factors related to it in the Brazilian population.

Methods

Administration of a previously validated online screening questionnaire to a representative sample of the general population. The questionnaire was distributed and administered to anonymous volunteers representing the general Brazilian population using software designed for population analyses.

Results

253 women answered the questionnaire, 12.3 ± 4% (Confidence Interval [CI] 95%) of whom presented symptoms compatible with a high probability of being diagnosed with lipedema. Furthermore, anxiety, depression, hypertension, and anemia were also correlated with a high probability of the diagnosis.

Conclusions

The estimated prevalence of lipedema in the population of Brazilian women is 12.3%.

Lipedema prevalence and risk factors in Brazil

Abstract Background Lipedema is characterized as an abnormal deposition of fat in the buttocks and legs bilaterally that may be accompanied by swelling, pain, and tenderness. It is still often confused with more frequent conditions such as obesity and lymphedema. The estimated prevalence in Europe varies between 0.06% and 39%. Objectives To evaluate the prevalence of lipedema and identify health factors related to it in the Brazilian population. Methods Administration of a previously validated online screening questionnaire to a representative sample of the general population. The questionnaire was distributed and administered to anonymous volunteers representing the general Brazilian population using software designed for population analyses. Results 253 women answered the questionnaire, 12.3 ± 4% (Confidence Interval [CI] 95%) of whom presented symptoms compatible with a high probability of being diagnosed with lipedema. Furthermore, anxiety, depression, hypertension, and anemia were also correlated with a high probability of the diagnosis. Conclusions The estimated prevalence of lipedema in the population of Brazilian women is 12.3%.

Gastric Metabolomics Detects Helicobacter pylori Correlated Loss of Numerous Metabolites in Both the Corpus and Antrum

Helicobacter pylori is a chronic bacterial pathogen that thrives in several regions of the stomach, causing inflammation that can vary by site and result in distinct disease outcomes. Whether the regions differ in terms of host-derived metabolites is not known. We thus characterized the regional variation of the metabolomes of mouse gastric corpus and antrum organoids and tissue. The uninfected secreted organoid metabolites differed between the corpus and antrum in only seven metabolites as follows: lactic acid, malic acid, phosphoethanolamine, alanine, uridine, glycerol, and isoleucine. Several of the secreted chemicals were depleted upon H. pylori infection in both regions, including urea, cholesterol, glutamine, fumaric acid, lactic acid, citric acid, malic acid, and multiple nonessential amino acids. These results suggest a model in which H. pylori preferentially uses carboxylic acids and amino acids in complex environments, and these are found in both the corpus and antrum. When organoid metabolites were compared to mouse tissue, there was little overlap. The tissue corpus and antrum metabolomes were distinct, including antrum-elevated 5-methoxytryptamine, lactic acid, and caprylic acid, and corpus-elevated phospholipid products. The corpus and antrum remained distinct over an 8-month infection time course. The antrum displayed no significant changes between the time points in contrast to the corpus, which exhibited metabolite changes that were consistent with stress, tissue damage, and depletion of key nutrients, such as glutamine and fructose-6-phosphate. Overall, our results suggest that the corpus and antrum have largely but not completely overlapping metabolomes that change moderately upon H. pylori infection.

Structures of the ligand-binding domain of Helicobacter pylori chemoreceptor TlpA

Bacteria use chemoreceptor proteins to sense and navigate their chemical environments. The most common class of chemoreceptors are transmembrane proteins that sense chemical cues through binding of a small-molecule ligand to a periplasmic domain, which modulates the receptor's ability to stimulate reversal of the cell's flagella motors. The prevalent gastric pathogen Helicobacter pylori uses such membrane-bound chemoreceptors, called transducer-like proteins (Tlp), to colonize and persist within the stomach. TlpA has been implicated in sensing arginine, bicarbonate, and acid, but no experimentally determined protein structures of TlpA were available to better understand ligand binding and signal transduction. Here, we report three crystal structures of the periplasmic portion of TlpA, which contains tandem PAS/Cache domains, similar to a recently published structure of the lactate-sensing chemoreceptor TlpC from H. pylori. These structures are the first to show a tandem PAS/Cache-form chemoreceptor in its native homo dimer oligomer, and we identify residues that are key contributers to the dimer interface. We performed sequence analyses to identify TlpA and TlpC homologs and used residue conservation among these homologs to implicate regions important for the general tandem PAS/Cache fold, and residues specific to TlpA function. Comparisons with TlpC show that despite high similarity across the general structure, TlpA lacks the residues required to bind lactate, and instead contains a pocket almost entirely hydrophobic in nature.

Estimating prevalence of overweight or obese children and adolescents in small geographic areas using publicly available data

Introduction

Interventions for pediatric obesity can be geographically targeted if high-risk populations can be identified. We developed an approach to estimate the percentage of overweight or obese children aged 2 to 17 years in small geographic areas using publicly available data. We piloted our approach for Georgia.

Methods

We created a logistic regression model to estimate the individual probability of high body mass index (BMI), given data on the characteristics of the survey participants. We combined the regression model with a simulation to sample subpopulations and obtain prevalence estimates. The models used information from the 2001–2010 National Health and Nutrition Examination Survey, the 2010 Census, and the 2010 American Community Survey. We validated our results by comparing 1) estimates for adults in Georgia produced by using our approach with estimates from the Centers for Disease Control and Prevention (CDC) and 2) estimates for children in Arkansas produced by using our approach with school examination data. We generated prevalence estimates for census tracts in Georgia and prioritized areas for interventions.

Results

In DeKalb County, the mean prevalence among census tracts varied from 27% to 40%. For adults, the median difference between our estimates and CDC estimates was 1.3 percentage points; for Arkansas children, the median difference between our estimates and examination-based estimates data was 1.7 percentage points.

Conclusion

Prevalence estimates for census tracts can be different from estimates for the county, so small-area estimates are crucial for designing effective interventions. Our approach validates well against external data, and it can be a relevant aid for planning local interventions for children.