Incidence and risk factors for metabolic syndrome among urban, adult Sri Lankans: a prospective, 7-year community cohort, follow-up study.

BACKGROUND: The metabolic syndrome (MetS) is a clustering of abdominal obesity, diabetes and prediabetes, high cholesterol and high blood pressure, that confers an increased risk of cardiovascular disease. There is limited data on incidence of MetS from South Asia. This study investigated incidence and risk factors for new onset MetS in an urban adult Sri Lankan population. METHODS: Subjects (selected by age-stratified random sampling from the Ragama Medical Officer of Health area) were screened initially in 2007 (35-64 years) and re-evaluated in 2014 (42-71 years). On both occasions they were assessed by structured interview, anthropometric measurements, liver ultrasound, and biochemical/serological tests. MetS was diagnosed on International Diabetes Federation (IDF-2006) criteria. Total body fat (TBF) and visceral fat percentage (VFP) were measured in 2014, using body impedance method. Incidence and factors at baseline, associated with new onset MetS, were investigated among those who presented for re-evaluation. RESULTS: 2985 (99.1%) [1636 (54.8%) women (54.8%); median age (IQR) 53 (47-59) years] from the initial cohort in 2007 had complete data. 2148 (71.9%) [1237 (57.6%) women; median age (IQR) 60 (54-66) years] attended follow-up. 949 of them [701 (73.9%) women; median age (IQR) 60 (54-65) years] had MetS (prevalence 47.2%, 95% CI 45.0-49.4%). Of 1246 who did not have MetS in 2007, 265 [178 (67.1%) women, median age (IQR) 57 (51-64) years] had developed MetS after 7 years (annual incidence 3.5% (95% CI 2.4-4.5%). Females (OR = 4.9, 95% CI 3.4-7.4), BMI > 23 kg/m2 in 2007 (OR = 1.6 per unit increase, 95% CI 1.5-1.7), weight gain (by 2-5% OR = 2.0, 95% CI 1.1-3.5; by > 5% OR = 2.2, 95% CI 1.4-3.4), and increase in waist circumference (by 2-5% OR = 7.0, 95% CI 4.0-12.2; by > 5% OR = 13.4, 95% CI 8.3-22.4) from baseline and presence of non-alcoholic fatty liver disease (NAFLD) in 2007 (OR = 1.70, 95% CI 1.04-2.76) were associated new onset MetS. Those with MetS had abnormal VFP and TBF in 2014 [P < 0.001]. CONCLUSION: In this study, annual incidence of MetS was 3.5%. Female gender, BMI > 23 kg/m2 and NAFLD in 2007 and increase in weight and waist circumference from baseline were significantly associated with new onset MetS. Obesity was the best predictor of future MetS.

Incidence and risk factors for non-alcoholic fatty liver disease: A 7-year follow-up study among urban, adult Sri Lankans.

BACKGROUND: This study investigated incidence and risk factors for NAFLD among an adult cohort with 7-year follow-up. METHODS: The study population (age-stratified random sampling, Ragama MOH area) was screened initially in 2007 (aged 35-64 years) and re-evaluated in 2014 (aged 42-71 years). On both occasions assessed by structured interview, anthropometric measurements, liver ultrasound, biochemical and serological tests. NAFLD was diagnosed on ultrasound criteria, safe alcohol consumption and absence of hepatitis B/C markers. Non-NAFLD controls did not have any ultrasound criteria for NAFLD. An updated case-control genetic association study for 10 selected genetic variants and NAFLD was also performed. RESULTS: Out of 2985 of the original cohort, 2148 (72.0%) attended follow-up (1238 [57.6%] women; mean-age 59.2 [SD-7.6] years) in 2014, when 1320 (61.5%) were deemed NAFLD subjects. Out of 778 who initially did not have NAFLD and were not heavy drinkers throughout follow-up, 338 (43.4%) (221 [65.4%] women, mean-age 57.8 [SD-8.0] years) had developed NAFLD after 7-years (annual incidence-6.2%). Central obesity (OR=3.82 [95%-CI 2.09-6.99]), waist increase >5% (OR=2.46 [95%-CI 1.20-5.05]) overweight (OR=3.26 [95%-CI 1.90-5.60]), weight gain 5%-10% (OR=5.70 [95%-CI 2.61-12.47]), weight gain >10% (OR=16.94 [95%-CI 6.88-41.73]), raised plasma triglycerides (OR=1.96 [95%-CI 1.16-3.29]) and diabetes (OR=2.14 [95%-CI 1.13-4.06]), independently predicted the development of incident NAFLD in multivariate analysis. The updated genetic association study (1362-cases, 392-controls) showed replicated association (P=.045, 1-tailed) with NAFLD at a candidate locus: PNPLA3 (rs738409). CONCLUSIONS: In this community cohort study, the annual incidence of NAFLD was 6.2%. Incident NAFLD was associated with general and central obesity, raised triglycerides and diabetes, and showed a tendency of association with PNPLA3 gene polymorphisms.

Diagnosis of Leptospirosis: Comparison between Microscopic Agglutination Test, IgM-ELISA and IgM Rapid Immunochromatography Test.

BACKGROUND: Leptospirosis is diagnosed on clinical grounds, and confirmed by microscopic agglutination test (MAT). IgM-ELISA (Serion-Virion) and immunochromatography test (Leptocheck-WB) are two immunodiagnostic assays for leptospirosis. Their sensitivity, specificity and applicability in Sri Lanka have not been systematically evaluated. METHODS: Clinically diagnosed leptospirosis patients (n = 919) were recruited from three hospitals in the Western Province of Sri Lanka, during June 2012 to December 2013. MAT, IgM-ELISA and Leptocheck-WB were performed on all patient sera. MAT titer of ≥ 400 in single sample, four-fold rise or seroconversion ≥ 100 in paired samples were considered as positive for MAT. For diagnostic confirmation, MAT was performed during both acute and convalescent phases. Anti-leptospiral IgM ≥ 20 IU/ml and appearance of a band in the test window were considered as positive for IgM-ELISA and Leptocheck-WB test respectively. Patients with an alternative diagnosis (n = 31) were excluded. Data analysis was performed using two methods, i) considering MAT as reference standard and ii) using Bayesian latent class model analysis (BLCM) which considers each test as imperfect. RESULTS: MAT, IgM-ELISA and Leptocheck-WB positivity were 39.8%, 45.8% and 38.7% respectively during the acute phase. Acute-phase MAT had specificity and sensitivity of 95.7% and 55.3% respectively, when compared to overall MAT positivity. IgM-ELISA and Leptocheck-WB had similar diagnostic sensitivity when compared with acute-phase MAT as the gold standard, although IgM-ELISA showed higher specificity (84.5%) than Leptocheck-WB (73.3%). BLCM analysis showed that IgM-ELISA and Leptocheck-WB had similar sensitivities (86.0% and 87.4%), while acute-phase MAT had the lowest sensitivity (77.4%). However, acute-phase MAT had high specificity (97.6%), while IgM-ELISA and Leptocheck-WB showed similar but lower specificity (84.5% and 82.9%). CONCLUSIONS: Both IgM-ELISA and Leptocheck-WB shows similar sensitivities and specificities. IgM-ELISA may be superior to MAT during the acute phase and suitable for early diagnosis of leptospirosis. Leptocheck-WB is suitable as a rapid immunodiagnostic screening test for resource limited settings.