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Gary Whitlock

Publications and source records attributed to Gary Whitlock.

10 recordsLinked to original sources
PubMed2005

Body mass index and mortality from ischaemic heart disease in a lean population: 10 year prospective study of 220,000 adult men.

BACKGROUND: Increased body mass index (BMI) is known to be related to ischaemic heart disease (IHD) in populations where many are overweight (BMI>or=25 kg/m2) or obese (BMI>or=30). Substantial uncertainty remains, however, about the relationship between BMI and IHD in populations with lower BMI levels. METHODS: We examined the data from a population-based, prospective cohort study of 222,000 Chinese men aged 40-79. Relative and absolute risks of death from IHD by baseline BMI were calculated, standardized for age, smoking, and other potential confounding factors. RESULTS: The mean baseline BMI was 21.7 kg/m2, and 1942 IHD deaths were recorded during 10 years of follow-up (6.5% of all such deaths). Among men without prior vascular diseases at baseline, there was a J-shaped association between BMI and IHD mortality. Above 20 kg/m2 there was a positive association of BMI with risk, with each 2 kg/m2 higher in usual BMI associated with 12% (95% CI 6-19%, 2P=0.0001) higher IHD mortality. Below this BMI range, however, the association appeared to be reversed, with risk ratios of 1.00, 1.09, and 1.15, respectively, for men with BMI 20-21.9, 18-19.9, and <18 kg/m2. The excess IHD risk observed at low BMI levels persisted after restricting analysis to never smokers or excluding the first 3 years of follow-up, and became about twice as great after allowing for blood pressure. CONCLUSIONS: Lower BMI is associated with lower IHD risk among people in the so-called normal range of BMI values (20-25 kg/m2), but below that range the association may well be reversed.

Adult↗
PubMed2003

Framingham Heart Study risk equation predicts first cardiovascular event rates in New Zealanders at the population level.

AIM: To establish the population-level predictive validity of the Framingham Heart Study risk equation used to derive cardiovascular disease risk-prediction charts for New Zealand management guidelines on raised blood pressure and dyslipidaemia. METHODS: During 1992-3, standard cardiovascular risk factors were measured in a cohort of 6354 people (4638 men and 1716 women) aged 35-74 years with no history of cardiovascular disease, who were either enrolled on Auckland general electoral rolls or employed by a nationwide multi-industry corporation. Five-year cardiovascular event rates were predicted for the cohort using a Framingham risk equation and were compared with observed five-year cardiovascular event rates for hospitalisation and mortality. RESULTS: Incident cardiovascular hospitalisations or death were reported for 411 cohort participants (325 men and 86 women) during five years of follow up. There was good agreement between observed and predicted five-year cardiovascular event rates in all five-year age/sex categories up to 69 years. The risk equation tended to underestimate risk slightly in men and overestimate risk slightly in women up to 69 years, while in 70- to 74-year-olds it was accurate for men. Its accuracy in older women is uncertain. CONCLUSION: A Framingham Heart Study risk equation used to estimate incident cardiovascular events in individuals without previous cardiovascular disease accurately predicts five-year risk of hospitalisation or death from a first cardiovascular event in New Zealand men aged 35-74 and women aged 35-69 years at the population level.

Adult↗
PubMed2003

Discriminative ability of a risk-prediction tool derived from the Framingham Heart Study compared with single risk factors.

AIM: To compare the discriminative ability of a multivariate risk-prediction model with individual continuous cardiovascular risk factors in a free-living population. METHODS: Standard cardiovascular risk factors were measured in 6354 participants (4638 men and 1716 women) aged 35 to 74 years with no history of cardiovascular disease either enrolled on Auckland general electoral rolls or employed by a New Zealand-wide multi-industry corporation, in 1992-3. The sensitivity and specificity of individual risk factors versus a five-year cardiovascular risk-prediction equation and the corresponding New Zealand risk charts in predicting hospitalisation and mortality from cardiovascular disease in the subsequent five-year period were estimated over a range of risk thresholds. RESULTS: Discrimination between individuals who had or did not have subsequent cardiovascular events was poor for individual risk factors. Increasing age had significantly more discriminability than blood pressure or lipids and the Framingham Heart Study risk tool had better discriminability than any single risk factor. CONCLUSIONS: A Framingham risk equation and corresponding New Zealand risk charts discriminate between individuals who will or will not experience hospitalisation or death from cardiovascular events. Discriminability is only modest but it is better than that achieved using individual risk factors.

Adult↗
PubMed2003

Blood pressure indices and cardiovascular disease in the Asia Pacific region: a pooled analysis.

This article aims to compare the importance of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP) as risk factors for stroke and ischemic heart disease and to assess whether the patterns are consistent by age and gender. Cox proportional-hazards regression, adjusted for cholesterol and smoking, was used to assess the associations of the 4 BP indices with stroke and ischemic heart disease by age and gender. The relative importance of individual indices was assessed with a hazard ratios for a 1-SD change in BP and by likelihood-ratio chi2 tests. The influence of >1 BP index in the Cox model was also estimated. The analyses demonstrated similar associations of SBP, DBP, and MAP with both fatal stroke and ischemic heart diseases, which were stronger than those of PP. Both SBP and MAP tended to be more important in the regression model than DBP or PP. In Cox models including DBP, addition of SBP improved the goodness of fit at all ages and for both genders. However, in Cox models including SBP, addition of DBP typically resulted in little incremental benefit over and above that of SBP alone. These data suggest that if time or resources are highly constrained, such as in much-needed epidemiologic surveys in developing countries, very little is lost from only measuring SBP.

Adult↗
PubMed2003

Is body mass index a risk factor for motor vehicle driver injury? A cohort study with prospective and retrospective outcomes.

OBJECTIVE: To investigate the association between risk of motor vehicle driver injury and body mass index (BMI). METHODS: In a cohort study of 10 525 New Zealand men and women, BMI was assessed in 1992-1993 (baseline), and data on deaths and hospitalizations for motor vehicle driver injury were obtained by record linkage to national health databases for the period 1988-1998. Hazard ratios (HR) and CI were estimated by Cox regression. RESULTS: During a mean 10.3 years of follow-up, 139 fatal and non-fatal driver injury cases occurred (85 before baseline and 54 after). A U-shaped association was observed between driver injury risk and BMI, both crudely and after adjustment for covariates, which included age, sex, driving exposure, and alcohol intake (P-values for quadratic trend </=0.02). Participants in the highest (>/=28.7 kg/m(2); HR = 2.00, 95% CI: 1.18-3.39) and lowest (<23.5 kg/m(2); HR = 2.17, 95% CI: 1.27-3.73) quartiles of BMI were twice as likely to have experienced a driver injury during the follow-up period as participants in the reference quartile (25.9-28.6 kg/m(2); HR = 1.00). CONCLUSION: Further research is needed to corroborate or refute the hypothesis that BMI is a risk factor for serious motor vehicle driver injury.

Accidents, Traffic↗
PubMed2002

Coronary heart disease and body mass index: a systematic review of the evidence from larger prospective cohort studies.

We systematically reviewed English-language publications arising from prospective cohort studies of the association between coronary heart disease risk and body mass index. Eighty published articles from 46 studies were identified. Two thirds of the studies, including all 14 studies with at least 500 cases ("larger" studies), reported a positive or J-shaped association. Among these 14 larger studies, the average increase in coronary heart disease risk for each 2 kg/m (2) higher body mass index was 14%. There was only limited evidence of effect modification by age, sex, ethnicity, or other variables. Evidence from many studies, including randomized controlled trials, implies that the association between coronary heart disease risk and body mass index is partly (or perhaps wholly) mediated by high blood pressure, dyslipidemia, and impaired glucose tolerance.

Adolescent↗