Metabolically healthy obesity in a young population assisted by the Family Health Strategy in Brazil

Background

Obesity is increasing in younger populations, and is associated with a high cardiovascular (CV) risk, however, it is not clear whether metabolically healthy obesity (MHO) may have a lower CV risk or if it is just an earlier stage of the disease.

Objective

To evaluate the prevalence and CV risk factors associated with MHO in a young population assisted by a Family Health Care unit in a large urban center in Brazil.

Methods

A cross-sectional population study for CV risk assessment in adults aged 20-50 years old from a FHC unit in Rio de Janeiro. Demographic, anthropometric data and CV risk factors were recorded. All underwent office blood pressure (OBP) measurements, laboratory evaluation (lipid and glycidic profile). Obesity was defined as a BMI ≥ 30 kg/m2 and MHO are those who have less than 3 of the following criteria: hypertension, diabetes, total cholesterol ≥ 200 mg/dL, HDL<40 mg/dL (men) and 50 mg/dL (women), triglycerides>150 mg/dL and increased waist circumference.

Results

A total of 632 individuals were evaluated (60% female; mean age 37 ± 9 years). The prevalence of obesity was 26%, of which 73% were classified as MHO. Obeses are older, with a higher prevalence of physical inactivity (51% vs 41%, p = 0.03), hypertension (44% vs 19%, p < 0.001), dyslipidemia (50% vs 36%, p = 0.002) and diabetes (7% vs 2%, p = 0.001) with higher systolic OBP. MHO compared to unhealthy ones are significantly younger and smoke less. Despite being obese, they have lower BMI (33.6 vs 35.2 kg/m2, p = 0.02) and abdominal circumference (102 vs 110 cm, p = 0.03), with lower diastolic BP.

Conclusions

MHO was more prevalent in this young population and seems to have a lower CV risk, however it is not clear whether these younger and less obese individuals are only at an earlier stage of the disease. Perhaps the CV diseases onset is postponed for a few years. Even so, these individuals should not be excluded from public health policies as a form of primary prevention.

Key messages

In this young population, MHO was more prevalent and presented a lower CV risk. The follow-up of MHO will show if they are really healthy or if they are at an early stage of the disease.

Cardiovascular risk factors and social determinants in a population study in Rio de Janeiro, Brazil

Background

The association of cardiovascular (CV) diseases and their risk factors with socioeconomic status has been well described, but its influence is often underestimated in epidemiological studies in Brazil.

Objective

To evaluate the relationship between the main CV risk factors and socioeconomic indicators in a population of adults registered in a Family Health Care (FHC) unit in a great urban center - Rio de Janeiro, Brazil.

Methods

Cross-sectional population study that included adults aged between 20 and 50 years living in the area covered by the FHC unit in Rio de Janeiro. Demographic data (gender and age), socioeconomic data (education level, profession, employment), CV risk factors (smoking, sedentary lifestyle, obesity, hypertension, diabetes, dyslipidemia) were recorded. The metabolic profile is evaluated through laboratory tests. Those who studied up to high school were considered poorly educated.

Results

604 individuals were enrolled [39% male, mean age: 38.8 ± 8,9 years] The median of schooling was 12 years. 288 individuals had high schooling, 44.5% were male. A total of 130 individuals did not study or work. Women with low education had a higher risk of smoking, obesity and hypertension with no difference regarding labor or study activities. Otherwise, men with low education had a higher risk of sedentary lifestyle and hypertension. Among men, not working or studying increased the risk of smoking and hypertension.

Conclusions

We found an inverse association between socioeconomic conditions and the prevalence of CV risk factors. Women are more affected by low schooling, while men are more affected by their working occupation. The study suggests that socioeconomic factors influence the CV risk, affecting men and women differently, pointing to the need for more comprehensive public health policies that effectively reverse this situation.

Key messages

We found an inverse association between socioeconomic conditions and the prevalence of CV risk factors. Socioeconomic factors influence cardiovascular risk differently according to gender.

Cytoplasmic dilution induces antidiuretic hormone water channel retrieval in toad urinary bladder

Antidiuretic hormone (ADH) increases the osmotic water permeability (Pf) of the toad urinary bladder by insertion of water channels into the apical cell membrane. Transepithelial water flow (Jv) reduces Pf by inducing endocytosis of apical water channels despite continuous ADH stimulation. This phenomenon is termed flux inhibition. We wished to determine whether cytoplasmic dilution or transcellular Jv causes flux inhibition because both have been proposed previously as a primary regulatory mechanism for this process. Apical membrane endocytosis was quantified by monitoring the uptake of the fluid phase marker fluorescein isothiocyanate dextran (FITC-dextran). FITC-dextran fluorescence was monitored in Triton X-100 extracts of epithelial cells as the ratio of total tissue fluorescence compared with background fluorescence. The background was defined as cellular autofluorescence and nonspecific tissue staining due to the presence of small amounts of free fluorescein contaminating the FITC-dextran. FITC-dextran uptake measured under symmetric isotonic (220 mosmol/kgH2O) conditions in either the absence (1.0 +/- 0.4 SD; n = 14) or presence (1.3 +/- 0.3; n = 4) of ADH was not statistically different from that of background. In contrast, flux inhibition induced by a 180 mosmol/kgH2O apical-to-basolateral osmotic gradient increased FITC-dextran uptake to 3.4 +/- 1.3 (n = 7). FITC-dextran uptake was identical in bladders exposed to symmetric hypotonic (150 mosmol/kgH2O) solutions during ADH (3.6 +/- 0.9; n = 6) or adenosine 3',5'-cyclic monophosphate (3.1 +/- 0.4 fold; n = 3) stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional and structural characterization of endosomes from toad bladder epithelial cells

Previous functional studies of toad bladder endosomes have been complicated by the presence of multiple endosome subpopulations each possessing different permeability characteristics. To identify and characterize both water channel-containing vesicles (WCV) and other endosome subpopulations, we combined flow cytometry, electron microscopy, stop-flow fluorometry, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Flow cytometry of endosomes identified distinct populations of fluorescein-labeled endosomes in bladders after removal of antidiuretic hormone (ADH) stimulation (ADH withdrawal). Centrifugation separated the larger fluorescein-labeled vesicles, sedimenting at lower speed (intermediate pellet, IP), from the smaller fluorescein-labeled vesicles, sedimenting at high speed (high-speed pellet, HSP). Permeability and structural studies of these subpopulations revealed the following. 1) IP endosomes labeled 10 min after ADH withdrawal (ADH IP) represented a highly purified population of WCV with high water permeability (Pf) that exhibited a low-activation energy and sensitivity to organic mercurials. 2) IP endosomes from unstimulated bladders did not contain functional water channels. 3) HSP from either ADH withdrawal or unstimulated bladders exhibited low Pf and acidified after addition of extravesicular ATP; moreover, protein compositions of purified HSP were distinct from those of purified IP. These results suggest that HSPs represent constitutive and not ADH-sensitive endosomes. 4) High permeability to protons (PH+) was seen in ADH IP endosomes but not the other fractions, providing strong evidence that the ADH water channel conducts protons. 5) Multivesicular bodies (MVB) exhibited low Pf and PH+, indicating that they do not possess functional water channels.(ABSTRACT TRUNCATED AT 250 WORDS)