Tanvir Chowdhury Turin

The University of Calgary, Calgary, Alberta, Canada

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Publications (122)451.52 Total impact

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    ABSTRACT: Uric acid is associated with hypertension and increased renin–angiotensin system activity, although this relationship diminishes after chronic exposure to high levels. Uric acid is more strongly associated with poor outcomes in women compared to men, although whether this is due to a sex-specific uric acid-mediated pathophysiology or reflects sex differences in baseline uric acid levels remains unknown. We examined the association between uric acid and vascular measures at baseline and in response to angiotensin-II challenge in young healthy humans. Fifty-two subjects (17 men, 35 premenopausal women) were studied in high-salt balance. Serum uric acid levels were significantly higher in men compared to women (328 ± 14 μmol/L vs. 248 ± 10 μmol/L, P < 0.001), although all values were within normal sex-specific range. Men demonstrated no association between uric acid and blood pressure, either at baseline or in response to angiotensin-II. In stark contrast, a significant association was observed between uric acid and blood pressure at baseline (systolic blood pressure, P = 0.005; diastolic blood pressure, P = 0.02) and in response to angiotensin-II (systolic blood pressure, P = 0.035; diastolic blood pressure, P = 0.056) in women. However, this sex difference lost significance after adjustment for baseline uric acid. When all subjects were stratified according to high (>300 μmol/L) or low (≤300 μmol/L) uric acid levels, only the low uric acid group showed a positive association between uric acid and measures of vascular tone at baseline and in response to angiotensin-II. Differences in uric acid-mediated outcomes between men and women likely reflect differences in exposure to increased uric acid levels, rather than a sex-specific uric acid-mediated pathophysiology.
    Physiological Reports. 12/2014; 2(12).
  • Tanvir Chowdhury Turin, Yoshikuni Kita, Nahid Rumana
    Journal of Epidemiology and Global Health. 11/2014;
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    ABSTRACT: Obstructive sleep apnea (OSA) is common among patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Home sleep testing is used to diagnose OSA in many studies investigating sleep-disordered breathing in this population. However, failure to successfully complete the test is a significant source of participant exclusion from research studies and delayed diagnosis in clinical practice. The objective of the study was to identify potential factors impeding acceptance and successful completion of home sleep testing in patients with kidney disease.
    11/2014;
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    ABSTRACT: Chronic kidney disease (CKD) is known to be one of the causes of cardiovascular disease and end-stage renal disease. Among the several treatable risk factors of CKD, that of dyslipidemia is relatively controversial. To clarify the association of polymorphisms in genes involved in lipid metabolism with the risk of CKD in the Japanese population, we used cross-sectional data from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study.
    Lipids in Health and Disease 10/2014; 13(1):162. · 2.31 Impact Factor
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    ABSTRACT: Lower estimated glomerular filtration rate (eGFR) on a single occasion is associated with risk of cardiovascular events; whether the degree of change in eGFR during a 1-year period adds prognostic information is unknown.
    Journal of the American Heart Association. 09/2014; 3(5).
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    ABSTRACT: Split-night polysomnography is performed at our centre in all patients with ALS who require assessment for nocturnal hypoventilation and their response to non-invasive ventilation. The purpose of this study was to determine how successful this practice has been, reflected by whether a complete assessment was achieved by a single split-night polysomnogram. We undertook a systematic, retrospective review of all consecutive split-night polysomnograms in ALS patients between 2005 and 2012. A total of 47 cases were reviewed. Forty-three percent of patients had an incomplete test, resulting in a recommendation to repeat the polysomnogram. Poor sleep efficiency and absence of REM sleep in the diagnostic portion of the study were strongly associated with incomplete studies. Clinical variables that reflect severity of ALS (FVC, PaCO2, ALSFRS-R) and use of REM-suppressing antidepressants or sedative-hypnotics were not associated with incomplete split-night polysomnogram. In conclusion, a single, split-night polysomnogram is frequently inconclusive for the assessment of nocturnal hypoventilation and complete titration of non-invasive positive pressure ventilation in patients with ALS. Poor sleep efficiency and absence of REM sleep are the main limitations of split-night polysomnography in this patient population.
    Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration 08/2014; · 2.37 Impact Factor
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    ABSTRACT: Patients with end-stage kidney disease (ESKD) have a high rate of mortality and specifically an increased risk of sudden cardiac death (SCD). Impaired cardiac autonomic tone is associated with elevated risk of SCD. Moreover, patients with ESKD are often vitamin D deficient, which we have shown may be linked to autonomic dysfunction in humans. To date, it is not known whether vitamin D supplementation normalizes cardiac autonomic function in the high-risk ESKD population. The VITamin D supplementation and cardiac Autonomic tone in Hemodialysis (VITAH) randomized trial will determine whether intensive vitamin D supplementation therapies improve cardiac autonomic tone to a greater extent than conventional vitamin D supplementation regimens in ESKD patients requiring chronic hemodialysis.
    BMC Nephrology 08/2014; 15(1):129. · 1.64 Impact Factor
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    ABSTRACT: Abstract Objective: Men have high cardiovascular risk and unfavourable cardiac autonomic tone compared to premenopausal women. The role of sex hormones in control of autonomic tone is unclear. We sought to determine the association between sex hormones and cardiosympathovagal tone at baseline and in response to a physiological stressor. Methods: Forty-eight healthy subjects (21 men, 27 premenopausal women) were studied in high-salt balance. Cardiac autonomic tone was assessed by heart rate variability, calculated by spectral power analysis (low frequency (LF, a measure of sympathetic modulation), high frequency (HF, a measure of vagal modulation) and LF:HF (a measure of cardiosympathovagal balance)) at baseline and in response to graded Angiotensin II (AngII) infusion (3 ng/kg/min × 30 min, 6 ng/kg/min ×30 min) were measured. The primary outcome was association between endogenous sex hormone levels and measures of cardiac autonomic tone. Results: All subjects had sex hormone levels in the normal range. No associations were observed between sex hormones and baseline cardiac autonomic tone in men or women. Men with lower testosterone levels, however, were unable to maintain both cardiosympathetic (p = 0.045) and cardiovagal tone (p = 0.035) in response to AngII even after adjustments for covariates. No association was observed between estradiol and progesterone and cardiac autonomic response to AngII in either sex. Conclusion: An unfavourable shift in the cardiac autonomic tone in men with lower testosterone levels was observed in response to a stressor. Understanding the role of sex hormones in modulation of cardiac autonomic tone may help guide risk reduction strategies in men.
    Clinical and experimental hypertension (New York, N.Y. : 1993). 07/2014;
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    ABSTRACT: IMPORTANCE The established chronic kidney disease (CKD) progression end point of end-stage renal disease (ESRD) or a doubling of serum creatinine concentration (corresponding to a change in estimated glomerular filtration rate [GFR] of -57% or greater) is a late event. OBJECTIVE To characterize the association of decline in estimated GFR with subsequent progression to ESRD with implications for using lesser declines in estimated GFR as potential alternative end points for CKD progression. Because most people with CKD die before reaching ESRD, mortality risk also was investigated. DATA SOURCES AND STUDY SELECTION Individual meta-analysis of 1.7 million participants with 12 344 ESRD events and 223 944 deaths from 35 cohorts in the CKD Prognosis Consortium with a repeated measure of serum creatinine concentration over 1 to 3 years and outcome data. DATA EXTRACTION AND SYNTHESIS Transfer of individual participant data or standardized analysis of outputs for random-effects meta-analysis conducted between July 2012 and September 2013, with baseline estimated GFR values collected from 1975 through 2012. MAIN OUTCOMES AND MEASURES End-stage renal disease (initiation of dialysis or transplantation) or all-cause mortality risk related to percentage change in estimated GFR over 2 years, adjusted for potential confounders and first estimated GFR. RESULTS The adjusted hazard ratios (HRs) of ESRD and mortality were higher with larger estimated GFR decline. Among participants with baseline estimated GFR of less than 60 mL/min/1.73 m2, the adjusted HRs for ESRD were 32.1 (95% CI, 22.3-46.3) for changes of -57% in estimated GFR and 5.4 (95% CI, 4.5-6.4) for changes of -30%. However, changes of -30% or greater (6.9% [95% CI, 6.4%-7.4%] of the entire consortium) were more common than changes of -57% (0.79% [95% CI, 0.52%-1.06%]). This association was strong and consistent across the length of the baseline period (1 to 3 years), baseline estimated GFR, age, diabetes status, or albuminuria. Average adjusted 10-year risk of ESRD (in patients with a baseline estimated GFR of 35 mL/min/1.73 m2) was 99% (95% CI, 95%-100%) for estimated GFR change of -57%, was 83% (95% CI, 71%-93%) for estimated GFR change of -40%, and was 64% (95% CI, 52%-77%) for estimated GFR change of -30% vs 18% (95% CI, 15%-22%) for estimated GFR change of 0%. Corresponding mortality risks were 77% (95% CI, 71%-82%), 60% (95% CI, 56%-63%), and 50% (95% CI, 47%-52%) vs 32% (95% CI, 31%-33%), showing a similar but weaker pattern. CONCLUSIONS AND RELEVANCE Declines in estimated GFR smaller than a doubling of serum creatinine concentration occurred more commonly and were strongly and consistently associated with the risk of ESRD and mortality, supporting consideration of lesser declines in estimated GFR (such as a 30% reduction over 2 years) as an alternative end point for CKD progression.
    JAMA The Journal of the American Medical Association 06/2014; · 29.98 Impact Factor
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    ABSTRACT: Background Few comprehensive stroke and acute myocardial infarction registries of long duration exist in Japan to illustrate trends in acute case-fatality of stroke and acute myocardial infarction with greater precision. We examined 17-year case-fatality rates of stroke and acute myocardial infarction using an entire community-monitoring registration system to investigate trends in these rates over time in a Japanese population.Methods Data were obtained from the Takashima Stroke and AMI Registry covering a stable population of approximately 55 000 residents of Takashima County in central Japan. We divided the total observation period of 17 years into four periods, 1989–1992, 1993–1996, 1997–2000, and 2001–2005. We calculated gender, age-specific and age-adjusted acute case-fatality rates (%) of stroke and acute myocardial infarction across these four periods.ResultsDuring the study period of 1989–2005, there were 341 fatal cases within 28 days of onset among 2239 first-ever stroke events and 163 fatal cases among 433 first-ever acute myocardial infarction events. The age-adjusted acute case-fatality rate of stroke was 14·9% in men and 15·7% in women. The age-adjusted acute case-fatality rate of acute myocardial infarction was 34·3% in men and 43·3% in women. The age-adjusted acute case-fatality rates of stroke and acute myocardial infarction showed insignificant differences across the four time periods. The average annual change in the acute case-fatality rate of stroke (−0·2%; 95% CI: −2·4–2·1) and acute myocardial infarction (2·7%; 95% CI: −0·7–6·1) did not change significantly across the study years.Conclusions The acute case-fatality rates of stroke and acute myocardial infarction have remained stable from 1989 to 2005 in a rural and semi-urban Japanese population.
    International Journal of Stroke 06/2014; · 4.03 Impact Factor
  • Mohammad Al Mamun, Nahid Rumana, Yoshikuni Kita, Tanvir Chowdhury Turin
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    ABSTRACT: Detailed research initiatives are required to get a clear scenario on complete characterization of environmental triggers in relation to conventional cardiovascular risk factors.
    Environmental Pollution 04/2014; · 3.73 Impact Factor
  • International journal of cardiology 01/2014; · 6.18 Impact Factor
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    ABSTRACT: Spontaneous intracerebral hemorrhage (ICH) is a devastating form of stroke with a poor prognosis overall. We conducted a systematic review and meta-analysis to identify and describe factors associated with early neurologic deterioration (END) after ICH. We sought to identify any factor which could be prognostic in the absence of an intervention. The Cochrane Library, EMBASE, the Global Health Library, and PubMed were searched for primary studies from the years 1966 to 2012 with no restrictions on language or study design. Studies of patients who received a surgical intervention or specific experimental therapies were excluded. END was defined as death, or worsening on a reliable outcome scale within seven days after onset. 7,172 abstracts were reviewed, 1,579 full-text papers were obtained and screened. 14 studies were identified; including 2088 patients. Indices of ICH severity such as ICH volume (univariate combined OR per ml:1.37, 95%CI: 1.12-1.68), presence of intraventricular hemorrhage (2.95, 95%CI: 1.57-5.55), glucose concentration (per mmol/l: 2.14, 95%CI: 1.03-4.47), fibrinogen concentration (per g/l: 1.83, 95%CI: 1.03-3.25), and d-dimer concentration at hospital admission (per mg/l: 4.19, 95%CI: 1.88-9.34) were significantly associated with END after random-effects analyses. Whereas commonly described risk factors for ICH progression such as blood pressure, history of hypertension, and ICH growth were not. This study summarizes the evidence to date on early ICH prognosis and highlights that the amount and distribution of the initial bleed at hospital admission may be the most important factors to consider when predicting early clinical outcomes.
    PLoS ONE 01/2014; 9(5):e96743. · 3.53 Impact Factor
  • Renal Week 2013 (Nov 5-10): Annual Meeting and Scientific Exposition of the American Society of Nephrology; 11/2013
  • Annual Meeting and Scientific Exposition of the American Society of Nephrology; 11/2013
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    ABSTRACT: Brachial-ankle pulse wave velocity (baPWV) is a non-invasive measure of arterial stiffness obtained using an automated system. Although baPWVs have been widely used as a non-invasive marker for evaluation of arterial stiffness, evidence for the prognostic value of baPWV in the general population is scarce. In this study, we assessed the association between baPWV and future cardiovascular disease (CVD) incidence in a Japanese population. From 2002 to 2009, baPWV was measured in a total of 4164 men and women without a history of CVD, and they were followed up until the end of 2009 with a median follow-up period of 6.5 years. Hazard ratios (HRs) for CVD incidence according to baPWV levels were calculated using a Cox proportional hazards model adjusted for potential confounding factors, including seated or supine blood pressure (BP). During the follow-up period, we observed 40 incident cases of CVD. In multivariable-adjusted model, baPWV as a continuous variable was not significantly associated with future CVD risk after adjustment for supine BP. However, compared with lower baPWV category (<18 m s(-1)), higher baPWV (18.0 m s(-1)) was significantly associated with an increased CVD risk (HR: 2.70, 95% confidence interval: 1.18-6.19). Higher baPWV (18.0 m s(-1)) would be an independent predictor of future CVD event in the general Japanese population.Journal of Human Hypertension advance online publication, 31 October 2013; doi:10.1038/jhh.2013.103.
    Journal of human hypertension 10/2013; · 2.80 Impact Factor
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    ABSTRACT: The reason why coexistence of preserved estimated glomerular filtration rate (eGFR) and albuminuria contributes to a high risk of death and which cause of death increases all-cause mortality have not been elucidated. A total of 16,759 participants aged 40 to 69years with normal or mildly reduced eGFR (45-119ml/min/1.73m(2)) were enrolled and divided into six groups (group 1, eGFR: 90-119 without albuminuria; group 2, eGFR: 90-119 with albuminuria; group 3, eGFR: 60-89 without albuminuria (reference); group 4, eGFR: 60-89 with albuminuria; group 5, eGFR: 45-59 without albuminuria; group 6, eGFR: 45-59 with albuminuria) based on GFR estimated by using the CKD-EPI study equation modified by a Japanese coefficient and albuminuria (urine albumin-creatinine ratio ≥30mg/g). Outcomes included all-cause death (ACD), cardiovascular death (CVD) and neoplasm-related death (NPD). Multivariable-adjusted mortality rate ratios (RR) and their 95% confidence intervals (CIs) in the groups were estimated by Poisson's regression analysis. The highest risk of ACD (RR (95% CIs): 3.95 (2.08-7.52)), CVD (7.15 (2.25-22.7)) and NPB (3.25 (1.26-8.38)) was observed in group 2. Subjects in group 2 were relatively young and had the highest levels of body mass index, blood pressure and HbA1c and the highest prevalence of diabetes and metabolic syndrome. Coexistence of preserved eGFR and albuminuria increases risks for ACD, CVD and NPD. Relatively young metabolic persons having both preserved eGFR and albuminuria should be considered as a very high-risk population.
    International journal of cardiology 10/2013; · 6.18 Impact Factor
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    ABSTRACT: Spontaneous intracerebral hemorrhage (ICH) is widely considered to be the most devastating form of stroke in North America. Currently there is no clear understanding of the cost of treatment in Canada and thus no way of understanding how to manage ICH spending in this country. We used a cohort study design to report and to examine the cost of ICH hospital care in a Canadian health center during 1 decade. Economic, treatment, and patients data were obtained from clinical and administrative sources. Analyses were performed using 987 consecutive patients with ICH from 1999 to 2008. The total inflation-adjusted cost of care was highly variable (median cost per discharge, $10 544.45 and $363.54 [min] to $265 470.43 [max] United States Dollars). Total cost did not change significantly during the decade. Patients age (cost change per year older, -$114.06 and -$189.01 to -$38.78) and in-hospital mortality (cost change for death, -$5092.84 and -$6270.65 to -$3697.09) were significantly associated with lower cost, whereas Charlson Comorbidity Index (cost change for ≥1, $5726.27 and $3965.36 to $7755.45), having surgery (cost change for surgery, $25 499.78 and $20 813.95 to $30 933.06), and admission National Institutes of Health Stroke Scale (cost change for ≥15 points, $7800.20 and $1637.78 to $17 026.38) were significantly associated with higher cost. To our knowledge, this is the most thorough published study to date to report and to examine predictors of ICH treatment costs in Canada. This study provides evidence that it may be reasonable to consider patients age, probability of death, level of comorbidity, need for surgery, and baseline ICH severity when forecasting health spending.
    Stroke 10/2013; · 6.16 Impact Factor
  • Tanvir C Turin, Brenda R Hemmelgarn
    Kidney International 10/2013; 84(4):849. · 8.52 Impact Factor
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    ABSTRACT: Objective: Sex influences the cardiorenal risk associated with body mass index (BMI). We sought to investigate the role of the renin-angiotensin-aldosterone system in adiposity-mediated cardiorenal risk profiles in healthy, non-obese men and women. Design and Methods: Systemic and renal hemodynamic responses to angiotensin-II (AngII) as a function of BMI, waist and hip circumference, waist-hip ratio, as well as fat and lean mass were measured in 18 men and 25 women in high-salt balance, stratified by BMI (<25kg/m(2) (ideal body weight (IBW)) vs. ≥25kg/m(2) (overweight)). Results: In men (n=7) and women (n=14) of IBW, BMI was not associated with the systolic blood pressure (SBP) response to AngII. In contrast, overweight men (29±2kg/m(2) ) demonstrated a progressively more blunted vasoconstrictor SBP response to AngII challenge as BMI increased (p=0.007), even after adjustment for covariates. Women maintained the same relationship between BMI and the SBP response to AngII irrespective of weight status (p=0.2, IBW vs. overweight women). Compared to BMI, other adiposity measures showed similar associations to systemic AngII responsiveness in men but not in women. Increasing BMI was associated with a blunted renovasoconstrictor response to AngII in all subjects, but was more pronounced in men. Conclusion: Sex influences the effect of adiposity on vascular angiotensin-responsiveness.
    Obesity 08/2013; · 3.92 Impact Factor

Publication Stats

634 Citations
451.52 Total Impact Points

Institutions

  • 2011–2014
    • The University of Calgary
      • • Department of Community Health Sciences
      • • Department of Medicine
      • • Faculty of Medicine
      Calgary, Alberta, Canada
    • Nagoya University
      • Department of Preventive Medicine
      Nagoya-shi, Aichi-ken, Japan
  • 2006–2014
    • Shiga University of Medical Science
      • Department of Health Science
      Ōtu, Shiga, Japan
    • Fukushima Medical University
      • Department of Hygiene and Preventive Medicine
      Hukusima, Fukushima, Japan
  • 2011–2013
    • Iwate Medical University
      • • School of Medicine
      • • Department of Hygiene and Preventive Medicine
      Morioka-shi, Iwate-ken, Japan
  • 2011–2012
    • Chinook Regional Hospital
      Lethbridge, Alberta, Canada
  • 2010
    • Klinikum Ludwigshafen
      Ludwigshafen, Rheinland-Pfalz, Germany
  • 2007–2010
    • Kyoto Women's University
      Kioto, Kyōto, Japan
  • 2008
    • University Hospital Medical Information Network
      Edo, Tōkyō, Japan