Prehypertension and Cardiometabolic Risk Profile – Chiang et al
MS: 2577243199287869 - Cardio-metabolic risk factors in Asian adults with prehypertension
Second revision – authors’ responses to reviewer
Reviewer: Yoshitaka Murakami
The manuscript is becoming much better than it used to be. Two major concerns are still remained
in the manuscript.
We thank the reviewer for his time in reviewing our manuscript a second time. We have addressed
the reviewer’s comments and hope that both the editor(s) and reviewer find our responses
favourable.
1. The definition of the study population should be clear in the title, method and the
interpretation of the result.
I understood from your reply comment that the study population in this manuscript was the
people without hypertension, diabetes and self-reported cardiovascular disease. I have a concern
that readers of the manuscript do not recognize that the study population is _not_ the general
population in Singapore which include some hypertensive participants in the population. I think
that this study population is so called the ‘healthy population’ or non-hypertensive population.
You should notice this in the title, the method and the results and you should comments on this
issue in the discussion section. Otherwise, people will misunderstand this extremely high
prevalence of pre-hypertension, which never happen to the ‘general population’.
Thank you for this comment. This is a very good point and we have clarified our study population in
our title, methods, and the interpretation of the results. For instance:
Our title now reads:
“Cardio-metabolic risk factors and prehypertension in persons without diabetes,
hypertension, and cardiovascular disease”
Changes to our methods include the statistical section:
“In the current study, we examined the association between cardiometabolic risk factors and
prehypertension in an apparently healthy multi-ethnic Singaporeans without diabetes mellitus,
hypertension and preexisting CVD….”
Clarification to the results include:
“Overall characteristics of the study population without hypertension, diabetes, and selfreported CVD by ethnic groups are shown in Table 1a…”
2. Population attributable fraction (PAR) in the cross-sectional study is confusing for most
epidemiologists. I read your reply that Steenland K et al. have showed the PAR of cross-sectional
studies in their text. I have already checked this and understood what their opinion. I also found
that this is the only text that mentioned the PAR of cross-sectional studies. All other textbooks
and the methodological papers deal with the PAR of cohort studied and case-control studies, not
cross-sectional studies. Etiological relationships between exposure and an outcome, which cannot
examine from cross-sectional studies, is an essential point for PAR calculation. I think the use of
PAR is cross-sectional studies is a wrong concept and should be avoided. If you insist on calculating
such figures, you can replace PAR to other word such as ‘an overload from pre-hypertension’ or
‘extra prevalence from pre-hypertension’.
Thank you for this valuable comment. We are in agreement with the reviewer and have decided to
subsequently remove PAR and any discussion(s) related to it to from our manuscript.
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Prehypertension and Cardiometabolic Risk Profile – Chiang et al
In lieu of the valuable comments from the reviewer we have also updated our abstract as well. Our
abstract now reads as follows:
“Background: Prehypertension has been shown to be an early risk factor of cardiovascular disease
(CVD). We investigated the prevalence and pattern of cardiometabolic risk factors in prehypertension
in three ethnic Asian populations in Singapore.
Methods: We examined data from Chinese (n=1177), Malay (n=774), and Indian (n=985) adults aged
40-80 years who participated in three independent population based studies conducted from 20042012 in Singapore who were free of diabetes, hypertension and previous CVD. Prehypertension was
defined as systolic blood pressure (BP) 120-139 mm Hg or diastolic BP 80-89 mm Hg. Random blood
glucose, glycated haemoglobin (HbA1C), body mass index (BMI), triglycerides, low-density lipoprotein
(LDL) and high-density lipoprotein (HDL) cholesterol were examined as indicators of adverse
cardiometabolic profile.
The association between metabolic variables and prehypertension was examined using logistic
regression models adjusting for potential confounders.
Results: The prevalence of prehypertension was 59.8% (Chinese), 68.9% (Malays) and 57.7% Indians.
Higher levels of blood glucose, HbA1c and BMI were significantly associated with prehypertension in
all three ethnic groups, odds ratio (95% confidence interval) of prehypertension in Chinese, Malays
and Indians were: 1.42 (1.10, 1.83), 1.53 (1.05, 2.24), 1.49 (1.13, 1.98) for high-glucose; 3.50 (1.01,
12.18), 3.72 (1.29, 10.75), 2.79 (1.31, 5.94) for high-HbA1c; 1.86 (1.34, 2.56), 2.96 (2.10, 4.18), 1.68
(1.28, 2.20) for high-BMI. In addition, higher levels of LDL cholesterol in Chinese and higher levels of
triglycerides were significantly associated with prehypertension. These associations persisted when
metabolic variables were analysed as continuous variables.
Conclusions: Higher levels of blood glucose, HbA1c and BMI were associated with prehypertension in
all three ethnic groups in Singapore. Screening for prehypertension and lifestyle modifications could
potentially reduce the burden of CVD in otherwise healthy Asian adults living in Singapore”.
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