An equation to explain variations in blood NT-proBNP in ambulatory cardiac subjects.

BACKGROUND: NT-proBNP is being used as a biomarker for prognosticating and delineating cardiac dysfunction. The cut-off value for deciding normal versus abnormal levels has always been a point of contention since it depends on the degree of dysfunction as well as other associated conditions often termed non-cardiac factors and parameters. Such association had not been formally presented. OBJECTIVE: To determine the direction and magnitude of effect of cardiac and non-cardiac parameters on NT-proBNP variability. MATERIAL AND METHOD: The present study included 78 cardiac ambulatory patients with a history of heart failure and/or low left ventricular ejection fraction. Their cardiac and non-cardiac parameters were recorded at the time of blood sampling for NT-proBNP. Multivariate linear regression analysis was used to correlate cardiac and non-cardiac parameters with NT-proBNP level and, from this, a predictive equation was derived. RESULTS: Log [NT-proBNP (pmol/l)] was 1.424 + 0.348 (for EF of 18-27) + 0.636 (for EF < 18) + 0.021 CTR - 0.002 SMW- 0.326 for female + 0.430 Cr - 0.010 BW [EF = LV ejectionfraction in %; CTR = cardio-thoracic ratio in %; SMW = 6-minute walking distance in meters; Cr = serum creatinine in mg/dl; BW = body weight in kg]. The adjusted R-square for this regression was 0.659. Omitting the non-cardiac variables (sex, Cr, BW) would decrease the adjusted R-square to 0.493. CONCLUSION: Cut-off value for NT-proBNP concentration in subjects without severe systolic heart failure has to account for these non-cardiac factors.

Gender and ethnic differences in cardiovascular risks in Songkhla province, Thailand: the interASIA-south.

The subset of data on southern Thai InterAsia study conducted in 2000 was revisited in order to document gender and ethnic breakdown of prevalence of risk factors for cardiovascular diseases (CVD). Three hundred and seventy-five men and 630 women with overall mean +/- SD age of 53.2 +/- 11.7 years were recruited. Combined gender prevalences were: 21.1% for smoking, 15.5% for drinking, 21.8% for hypertension (systemic blood pressure > or = 140/90 mmHg), 49.8% for impaired fasting plasma glucose (FPG 110-125 mg/dl), 9.9% for diabetes mellitus (FPG > or = 126 mg/dl), 10% for body mass index > or = 30 kg/m2, 43.5% for large waist circumference (WC > or = 90 cm in men and > or = 80 in women), 62.8% for total serum cholesterol (TC), > 200 mg/dl, 38.5% for TC divided by high density lipoprotein cholesterol (HDL-C) > or = 5 and 61.6% for low-density-lipoprotein cholesterol (LDL-C), > or = 130 mg/dl. After using logistic regression, adjusting the effects of age and community of residence, women were less likely than men to be smokers, drinkers, or showed impaired FPG but significantly more likely to have large WC, TC > or = 200 mg/dl and LDL-C > or = 130 mg/dl. Muslims showed significantly lower risk for drinking and large WC but higher risk for low HDL-C. The differences require further research. In conclusion, gender and age have stronger association with various risk factors than ethnicity in this selected population.

Risk factors for a five-year death in the interASIA-south cohort.

OBJECTIVE: To determine the mortality rate and risk factors for death in a selected population in Songkhla province in southern Thailand. MATERIAL AND METHOD: The southern subjects were part of the Thai cohort which together with the cohort from China comprised the InterASIA survey which was conducted in the year 2000. Collected variables were the conventional ones and included the 2 ethnic groups which are specific for southern Thailand, i.e. Malay Muslims and Thai-Chinese Buddhists. Causes of death were determined by reviewing hospital records, verbal autopsies and a consensus by 2-3 physicians. Kaplan Meier's model was used to evaluate the independent factors related to death. RESULTS: The follow-up was 5 years. Out of the original 1,006 subjects, the status could be examined in 86% and of these, 50 had died giving the Kaplan Meier 5-year survival rate of 94.3%. Sixteen died from cardiovascular diseases (CVD), 6 from strokes and 10 from coronary heart disease, and 15 died from cancer. Half of the deaths occurred in subjects older than 70 years. Independent risks for death were age, hypertension and diabetes mellitus. Risk for the major causes of death did not include ethnicity. Similar to the only existing prospective report of risk factors for death in Thailand (the Electricity Generating Authority of Thailand study), neither high total cholesterol, high triglyceride nor obesity were independent risks for death from CVD, but the present study differed in that the high density lipoprotein cholesterol was not found to be a protective factor for CVD death. CONCLUSION: Risk factors for death in a five-year follow-up in Southern Thailand did not include lipids, ethnicity or urbanization but hypertension and diabetes mellitus did.

Loss of high density lipoprotein cholesterol in serum: effect of storage.

The objectives of the study were to determine the magnitude and pattern of loss of detectable high density lipoprotein cholesterol (HDL-C) as functions of time and temperature of storage. Serum from 29 consented adults were estimated for HDL-C (utilising polyethylene glycol and alpha-cyclodextrin) when freshly obtained and after storage at 4 degrees C, -20 degrees C and - 70 degrees C at varied intervals up to a maximum of 120 days. The concentration of fresh HDL-C ranged from 16.9 to 87.2 mg/dl. After 5 days of storing at 4 degrees C, an average of 5% of HDL-C could not be detected. After 120 days of storing at -20 degrees C, 6-8 mg/dl of HDL-C was 'lost, this represented 10-20% of the concentration of the fresh samples. Storage at -70 degrees C resulted in a 'loss' of 3%. The pattern of reduction of detectable HDL-C was such that the initial loss (first few days) was very rapid, reaching a nadir in 20 days. Examining individual serum samples, the loss ranged from minimal up to 30% of the original concentrations for all condition of storage. From further analysis of some portion of the data, there were suggestions that the concentration of triglyceride could be affect the loss of HDL-C with storage. Conclusion: Such rate of loss and heterogeneity of loss of detectable HDL-C, so far unexplained, may have implications in the management of epidemiological surveys involving storage of lipids in tropical countries.

Prevalence of cardiovascular risk factors in a rural area in Southern Thailand: potential ethnic differences.

In Thepa district, Songkhla province, Southern Thailand, parents of children being followed long term from conception for their development (N 1325), as well as health workers of the same district (N 150) were surveyed with regards to anthropometry, occupation, family size, food and leisure habits, and blood levels of lipids, sugar, creatinine and hematocrit. Differences among those of Thai or Chinese extracts (Thai-Buddhists) and those of Malay extracts (Thai-Muslims) were separately evaluated for males and females. The mean age for the group (N 1475, including 636 couples) was 31.5 +/- 7.3 (SD) and ranged from 15-66 years. There were 794 females (485 Muslims) ages 29.6 +/- 6.6 (SD). The Muslim families were larger in size averaging 2.8 +/- 1.6 children while the Buddhist's averaged 1.9 +/- 0.9. Fifty four percent of the group were engaged in rubber tapping and this often included both members of the family. Sixty eight percent of the males currently smoked Differences in measured variables between Muslims and Buddhists were minimal. The most striking however was the high density lipoprotein cholesterol (HDL-C) among the males where the age-adjusted average was 51.3 +/- 0.72 (SE) among the Buddhists and 42.2 +/- 0.59 (SE) in the Muslims. This difference was significant even when adjusted for other related variables. Differences in the ethnic groups were also examined in terms of prevalence of risks (hypertension, BMI > or = 25%, waist-hip-ratio, fasting plasma glucose > or = 110 mg%, total cholesterol > or = 200 mg%, triglyceride > or = 150 mg% and low HDL-C). For hypertension (systolic > or = 140 or diastolic > or = 90 mmHg), female Muslims showed higher prevalence (4.5% vs 1.6%; OR 2.82 CI 1.04-7.64). For low HDL-C, male Muslim showed higher prevalence 23.6 vs 8.8%, OR 2.31 CI 1.27-4.22). Other risks showed no differences among the ethnic groups. The differences in parameters or in prevalence of risk between these two ethnic groups (minimal intermarriage) are distinct from differences among Malays and Chinese in Singapore where such differences were subsequently reflected in the differences in incidence and out-come of ischemic heart diseases.

Varidans streptococci in the oral flora of the patients at risk for infective endocarditis: species and penicillin susceptibilities.

This study examined viridans streptococci (SV) in oral flora of patients at risk of infective endocarditis (IE) by obtaining 57 isolates from gum-tooth margin swabs of 3 groups of patients. Penicillin minimal inhibitory concentrations (MICs) were determined by E test. Group 1 was from 30 patients with prosthetic heart valves who did not receive antimicrobial agents within 3 months prior to recruitment. Group 2 consisted of 21 patients with known rheumatic heart diseases who regularly received penicillin prophylaxis. Group 3 was 2 patients with IE caused by SV in whom dental swabs were performed before and on the third day of treatment. Streptococcus mitis was found most frequently (49% among 51 oral isolates of SV from patients in group 1 and 2) and in both blood cultures of IE patients. Ninety-four per cent of the isolates were penicillin-susceptible and the rest were intermediate-resistant (IR) equally distributed in both groups 1 and 2. In 2 patients with IE, oral SV obtained after 3 days of penicillin therapy had MICs rising 3 and 5 folds of the baselines. It is suggested that surveillance of susceptibilities of oral SV in patients at risk for IE should be kept up since this will affect the dose and type of antimicrobial agents in IE prophylaxis.