RESUMO
BACKGROUND: In clinical practice, left ventricular hypertrophy (LVH) is defined by physical findings and electrocardiographic criteria, which are useful but imperfect tools, echocardiographic criteria and cardiac magnetic resonance imaging. In echocardiography, LVH is defined not by left ventricular wall thicknesses but by left ventricular mass. The latter is calculated according to Devereux's formula, and is increased by insulin resistance/hyperinsulinaemia. It is however unclear whether insulin resistance, hyperinsulinaemia, or both, is actually causative and what their collective or individual influence is on the components of Devereux's formula and parameters of left ventricular diastolic function. This study evaluated the associations of the homeostatic model assessment for insulin resistance (HOMAIR) and fasting plasma insulin levels with components of Devereux's formula and parameters of left ventricular diastolic function. METHODS: Relevant clinical data were collected from 220 hypertensive patients recruited between January and December 2019. The associations of components of Devereux's formula and parameters of diastolic function with insulin resistance were tested using binary ordinal, conditional and classical logistic regression models. RESULTS: Thirty-two (14.5%) patients (43.9 ± 9.1 years), 99 (45%) patients (52.4 ± 8.7 years) and 89 (40.5%) patients (53.1 ± 9.8 years) had normal left ventricular geometry, concentric left ventricular remodelling and concentric left ventricular hypertrophy, respectively. In multivariable adjusted analysis, 46.8% of variation in interventricular septum diameter (R² = 0.468; overall p = 0.001) and 30.9% of E-wave deceleration time (R² = 0.309; overall p = 0.003) were explained by insulin level and HOMAIR, 30.1% of variation in left ventricular end-diastolic diameter (R² = 0.301; p = 0.013) by HOMAIR alone, and 46.3% of posterior wall thickness (R² = 0.463; p = 0.002) and 29.4% of relative wall thickness (R² = 0.294; p = 0.007) by insulin level alone. CONCLUSIONS: Insulin resistance and hyperinsulinaemia did not have the same influence on the components of Devereux's formula. Insulin resistance appeared to act on left ventricular end-diastolic diameter, while hyperinsulinaemia affected the posterior wall thickness. Both abnormalities acted on the interventricular septum and contributed to diastolic dysfunction via the E-wave deceleration time.
RESUMO
BACKGROUND: This study determined the diagnostic performance of new biomarkers for a composite diagnosis of non-communicable diseases (NCDs) among Central Africans. METHODS: This case-control study was conducted at LOMO Medical Centre, Kinshasa, DR Congo (DRC) between January - December, 2008. The cases comprised 226 participants with concurrent presence of at least 2 or more of NCDs. Anthropometric parameters and blood pressure were measured while blood samples were assayed for biomarkers. The receiver operating characteristics curve and the logistic regression model were applied. RESULTS: Serum selenium (Se) had specificity and sensitivity of 72.4% and 91.1%, respectively with an area under the curve (AUC) of 0.802; Nitric oxide (NO) (specificity: 72.4%; sensitivity: 93.0%) (AUC = 0.800); Thyroid stimulating hormone (TSH) levels > 6 Mu/L (specificity: 75%; sensitivity: 65%) (AUC = 0.0.727); serum calcium levels of ≥ 110g/L (specificity: 76%; sensitivity: 75%) (AUC = 0.822); and daily salt intake of ≥10 g/day (specificity: 75%; sensitivity: 67%) (AUC = 0.653) in the diagnosis of all NCDs, which were all highly significant (<0.0001). CONCLUSION: Serum Se, NO, calcium, TSH and daily salt intake had high diagnostic performance as biomarkers for identification of patients with concurrent NCDs in the study population.
