physical activity level and dyslipidemia

SOUTHEAST ASIAN J TROP MED PUBLIC HEALTH

932 Vol 39 No. 5 September 2008

Correspondence: Dr Vitool Lohsoonthorn, Univer-sity of Washington, MIRT Program, Department ofEpidemiology (Box 357236), University of Wash-ington (HSB F-263), 1959 NE Pacific Street,Seattle, WA, 98195, USA.Tel: (206) 543-7559; Fax: (206) 543-8525E-mail: [email protected]

RISK OF DYSLIPIDEMIA IN RELATION TOLEVEL OF PHYSICAL ACTIVITY

AMONG THAI PROFESSIONAL AND OFFICE WORKERS

1Cherell Dancy, 1, 2Vitool Lohsoonthorn and 1Michelle A Williams

1Department of Epidemiology, Multidisciplinary International Research Training Program,University of Washington School of Public Health and Community Medicine, Seattle,

Washington, USA; 2Department of Preventive and Social Medicine, Faculty of Medicine,Chulalongkorn University, Bangkok, Thailand

Abstract. We completed a cross-sectional study of 1,608 Thai participants (536 men and1,072 women) receiving annual health check-ups to evaluate the relation between physicalactivity levels and fasting serum concentrations of total cholesterol (TCH), triglyceride (TG),high density lipoprotein-cholesterol (HDL-C), and the total cholesterol: high density lipopro-tein-cholesterol (TCH:HDL-C) ratio. Physical activity levels were assessed using a self-admin-istered questionnaire administered at the time of blood collection. After controlling for con-founders, men who reported high physical activity levels had on average a 3.42 mg/dl higher(p=0.020) in HDL-C concentrations, when compared to men who reported low physical activ-ity levels. Higher mean HDL-C concentrations were also observed for women who reportedhigh physical activity levels, when compared with their less active counterparts (4.24 mg/dl,p=0.004). TG concentrations were 30.92 mg/dl lower in men (p=0.029) and 12.83 mg/dllower in women (p=0.003) who had high physical activity levels when compared with lessactive individuals. Men who reported high physical activity levels, compared with those whoreported low physical activity levels, had a 59% reduction in risk for hypertriglyceridemia(OR=0.41, 95% CI: 0.24-0.70). The corresponding OR for women was 0.43 (95%CI: 0.21-0.88). No association was found between physical activity levels and TCH concentrations.Overall, these data suggest that habitually active men and women are less likely to havehypertriglyceridemia and low HDL-C concentrations. The favorable effects of physical activityon lipid and lipoprotein concentrations are consistent with the evidence documenting the car-diovascular health benefits of physically active lifestyles.

INTRODUCTION

A large epidemiological, clinical, and ex-perimental literature clearly points to favorablephysiological changes and overall health ben-efits associated with regular physical activity

(DHHS, 1996). Benefits include favorable al-terations in plasma lipid and lipoprotein con-centrations, systolic and diastolic blood pres-sures, endothelial function, glycemic control,reductions in risk of essential hypertension,coronary heart disease, type 2 diabetes andcertain cancers, as well as increased longev-ity (DHHS, 1996). On the basis of this sub-stantial body of scientific evidence, the USCenters for Disease Control and Preventionand the American College of Sports Medicinehave recommended that adults should accu-mulate 30 minutes or more of moderate-in-

PHYSICAL ACTIVITY AND LIPID PROFILES

Vol 39 No. 5 September 2008 933

tensity physical activity on most, and prefer-ably all, days of the week. Moderate intensityphysical activity is defined as activity with anenergy requirement of 3-5 metabolic equiva-lents (METs). For a typical healthy adult, thisis equivalent to brisk walking at 3-4 miles perhour. In 2002, the Institute of Medicine notedthat at least 60 minutes of moderate-intensityphysical activity are necessary to preventweight gain, achieve a higher level of physicalfitness, and obtain the full health benefits ofactivity (IOM, 2002). That same year, recog-nizing the burden of chronic disease, and theglobal public health importance of combatingphysical inactivity, WHO adopted a resolutionto provide leadership to encourage physicalactivity within in their broader framework forchronic disease prevention and health promo-tion (WHO, 2002). Hence, guidelines pro-moted by several health organizations endorsemoderate and/or high intensity levels of physi-cal activity of varying durations as a healthpromotion and disease prevention modality forthe general adult population.

Results from clinical studies suggest thathypertension, chronic systemic inflammation,dyslipidemia and oxidative stress are commonpathophysiologic features of cardiovasculardisorders (Johnstone et al, 1996; Poulter,1999; Dhalla et al, 2000; Lopes et al, 2003).Taken together with evidence from observa-tional studies, controlled clinical trials, andanimal studies, suggests that physical activ-ity may impact the occurrence of cardiovas-cular disease through a number of overlap-ping and independent biological pathways.For instance, evidence from studies primarilyconducted in North America and Europe indi-cate that physiological effects of physical ac-tivity include improved insulin sensitivity, re-duced blood pressure, decreased concentra-tions of pro-inflammatory cytokines in periph-eral circulation, reduced oxidative stress andimproved plasma lipid and lipoprotein concen-trations (Mayer-Davis et al, 1998; Smith et al,

1999; He and Bazzano, 2000; Durstine et al,2001; Yeo and Davidge, 2001; Kraus et al,2002; Halverstadt et al, 2007; Slentz et al,2007). For example, Kobayashi et al (2006)recently reported that modest increases in ha-bitual walking are associated with reduced TGconcentrations among Japanese men. Al-though several investigators have evaluated in-fluences of lifestyle characteristics on metabolicparameters in Thai adults, none has assessedthe extent to which, if at all, habitual physicalactivity is associated with favorable lipid pro-files among Thai men and women. To fill thisgap in knowledge, we completed a cross-sec-tional study to evaluate the relation betweenlevels of physical activity and fasting plasmaconcentrations of total cholesterol (TCH), trig-lyceride (TG), high density lipoprotein-choles-terol (HDL-C), and the total cholesterol: highdensity lipoprotein-cholesterol ratio (TCH:HDL-C) among Thai professional and office workerswho took part in annual clinical examinations.

MATERIALS AND METHODS

Study population and data collection

We conducted a cross-sectional study of1,608 subjects (536 men and 1,072 women)who participated in annual health examinationsat the Mobile Health Checkup Unit of KingChulalongkorn Memorial Hospital in Bangkok,Thailand during the period of December 2006through February 2007. Each year, Chulalong-korn Memorial Hospital provides on-site annualhealth examinations to professional and officeworkers of approximately 45 private compa-nies and governmental agencies in and aroundBangkok. Given that blood chemistry are notroutinely measured on all participants under theage of 35 years, this research was restricted tothose participants who were ≥35 years of ageat the time of annual health examination. Eli-gible participants were asked to provide infor-mation about their age, marital status, occu-pation, educational attainment, medical history,



smoking status, and alcohol consumption hab-its. Information concerning physical activity wascollected using a self-administered GlobalPhysical Activity Questionnaire (GPAQ). Thequestionnaire, developed and validated by theWorld Health Organization (WHO) (2004), mea-sures three physical activity domains: occupa-tional activity, leisure time physical activity, andpurposeful activity for transportation (eg, walk-ing or cycling to work). Participants underwentroutine physical examinations which includingdetermining their height, weight, and collect-ing an overnight fasting venous blood sample.Standing height was measured without shoesto the nearest 0.5 centimeter. Weight was de-termined without shoes and with participantslightly clothed. Weight was measured using anautomatic electronic scale (Seca, Hamburg,Germany) to the nearest 100 grams.

Laboratory analyses

Serum samples were used to determineparticipants’ lipid and lipoprotein profiles.Serum triglyceride (TG) and total cholesterol(TCH) concentrations were determined usingstandardized enzymatic procedures. TG wasanalyzed by glycerol phosphate oxidase as-say. TCH was quantified using the Trinderendpoint reaction in an automatic chemistryanalyzer. High density lipoprotein-cholesterol(HDL-C) was measured by a chemical precipi-tation technique using dextran sulfate. Alllaboratory assays were completed withoutknowledge of participants’ medical history.Lipid and lipoprotein concentrations were re-ported as mg/dl.

All participants provided informed con-sent and the research protocol was reviewedand approved by the Ethics Committee of theFaculty of Medicine, Chulalongkorn University,and the Division of Human Subjects Research,University of Washington.

Analytical variable specification

Physical activity data were coded usingpreviously described procedures (WHO,

2004). Participants were classified into threecategories of total physical activity (high, mod-erate and low). The criteria for high physicalactivity participation were 3,000 MET (Meta-bolic Equivalent) minutes per week accumu-lated over 7 days or 1,500 MET minutes ofvigorous-intensity activity accumulated over 3days or more. Moderate physical activity par-ticipation was classified as 30 minutes of walk-ing or moderate-intensity activity on 5 or moredays, 20 minutes of vigorous-intensity activityon 3 or more days, or 600-2,999 total METminutes of activity over 7 days. Those notmeeting the criteria for either high or moder-ate levels of physical activity were classifiedas low physical act iv i ty part ic ipat ion.Participant’s body mass index (BMI) was cal-culated by expressing weight (kilograms) di-vided by height (meters) squared. BMI wasevaluated both as a continuous variable andas a categorical variable. We used the crite-ria proposed by WHO (1995) to classify par-ticipants as lean (BMI < 18.5 kg/m2), normal(18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30 kg/m2), respectively. Wecategorized participants’ age according todecade (<40, 40-49, 50-59, ≥60 years). Othercovariates were categorized as follows: edu-cation (<bachelor degree, bachelor degree,master degree, and PhD degree); cigarettesmoking history (never, previous and currentsmoker); alcohol consumption (non-currentand current).

Using the criteria of the National Choles-terol Education Program (NCEP) Adult Treat-ment Panel III (ATP III), high total cholesterolis defined as TCH ≥200 mg/dl. Hypertrigly-ceridemia is defined as TG ≥150 mg/dl. LowHDL-C is defined as HDL-C <40 mg/dl in menand <50 mg/dl in women (NCEP, 2001). Weperformed analyses separately for TCH, TGand HDL-C expressed as continuous vari-ables. The ratio of TCH and HDL-C is thoughtto be an integrative measure of dyslipidemia(Lemieux et al, 2001). Therefore, we calculated



the TCH/HDL-C ratio and repeated all gen-der-specific analyses using this integrative lipidmeasure.

Statistical analyses

We first explored frequency distributionsof socio-demographic, behavioral character-istics and medical histories. All data weresummarized and displayed as number andproportion of participants possessing eachcharacteristic (categorical variables). For con-tinuous variables, we report group-specificmeans and standard deviations (SD).

We used multivariable least squares lin-ear regression procedures to assess the in-fluence of physical activity on serum lipid andlipoprotein concentrations. Analyses werecompleted for each lipid marker (ie, TCH, TG,HDL-C, and TCH:HDL-C ratio). To assess con-founding, we entered covariates into a linearregression model one at a time and then com-pared coefficients. Final linear regression mod-els included covariates that altered unadjustedcoefficients by at least 10%. Adjusted R2 val-ues, representing the total variation of eachlipid marker explained by covariates in finalmodels, were also reported. Since there is noconsensus concerning how adiposity shouldbe model in evaluation of physical activity anddyslipidemia, we repeated the analysis afterstratify participants according to lean (BMI <25kg/m2) and overweight (BMI ≥25 kg/m2). Allanalyses were completed separately for maleand female patients.

We used logistic regression proceduresto estimate the relative risks of having clini-cally relevant high TCH (≥200 mg/dl), high TG(≥150 mg/dl) concentrations and low HDL-Cconcentrations (<40 in men and <50 inwomen) according to their habitual physicalactivity level (low, moderate and high activitylevels). Multivariable logistic regression pro-cedures were employed to calculate odds ra-tios (OR, measures of relative risk) while ad-justing for potential confounding factors.

Covariates were evaluated as potential con-founding factors on the basis of their hypoth-esized relationship with high TCH, high TG,low HDL-C, and physical activity status. Con-founding was assessed empirically by enter-ing covariates into logistic regression modelsone at a time, and by comparing adjusted andunadjusted ORs (Rothman and Greenland,1998). Final logistic regression models in-cluded covariates that altered unadjusted ORsby at least 10%. All statistical analyses wereperformed using SPSS (version 14.0, SPSS,Chicago, IL, USA) software. All reported p-values are two tailed, and confidence inter-vals were calculated at the 95% level.

RESULTS

Socio-demographic characteristics formale and female participants are presented inTable 1. Overall, this is a well-educated popu-lation, with more than 70% of the populationhaving at least a bachelor’s degree. We noteda great deal of variability in self-reported ha-bitual physical activity in this study population.Approximately 44% of men reported havinglow levels of physical activity, while 26% re-ported high levels of physical activity. Nota-bly, self-reported physical activity levels weremuch lower among women. Over 51% ofthese women reported low levels of physicalactivity with only 14.2% reporting high levelsphysical activity.

There was no evidence of associationsbetween serum TCH concentrations andphysical activity among men and women(Table 2). However, mean TG concentrationsdecreased across groups of men classified byincreasing level of physical activity (p for trend= 0.030). After controlling for potential con-founding, we noted that mean TG concentra-tions were 12.24 mg/dl (p = 0.364) loweramong men reporting to have moderate lev-els of activity, compared with men reportinglow levels of activity. Mean TG concentrations



na % na %

Age (Years)35-39 124 23.1 171 16.040-49 217 40.5 479 44.750-59 171 31.9 402 37.5≥60 24 4.5 20 1.9

Mean (SD)b 46.5 (7.6) 47.2 (6.8)

EducationLess than bachelor degree 155 29.3 209 19.7Bachelor degree 106 20.0 437 41.1Master degree 110 20.8 245 23.1PhD degree 158 29.9 171 16.1

Cigarette smoking statusNever smoker 328 61.7 1,009 95.1Previous smoker 108 20.3 36 3.4Current smoker 96 18.0 16 1.5

Alcohol consumption statusNon-current drinker 269 50.5 909 85.8Current drinker 264 49.5 150 14.2

Body mass index (kg/m2)<18.5 5 0.9 47 4.418.5-24.9 301 56.8 652 61.625.0-29.9 176 33.2 263 24.9≥30 48 9.1 96 9.1

Mean (SD)b 25.1 (3.5) 24.0 (4.2)

Level of physical activityLow 228 43.6 526 51.1Moderate 157 30.0 358 34.8High 138 26.4 146 14.2

Table 1Socio-demographic characteristics of study participants.

Men WomenCharacteristics (N=536) (N=1,072)

aNumber may not be added up to the total number due to missing databSD = Standard deviation

were 30.92 mg/dl lower among highly activitymen, compared with those reporting low ac-tivity (p = 0.029). A similar pattern of de-creased mean TG concentrations with increas-ing levels of physical activity was observedamong women (p for trend < 0.001). MeanTG concentrations were 10.35 mg/dl lower forwomen who were moderately active (p =0.001) and 12.83 mg/dl lower for highly ac-

tive women (p=0.003) when compared withwomen who had low levels of activity. Whenage, education, cigarette smoking, alcoholconsumption and body mass index (BMI) wereadjusted for, men who reported high levels ofphysical activity had HDL-C concentrationsthat were 3.42 mg/dl higher (p=0.020), onaverage, than concentrations in men who re-ported low levels of physical activity. Higher



Tab

le 2

Rel

atio

nshi

ps

of

seru

m li

pid

s an

d li

po

pr o

tein

co

ncen

trat

ions

with

leve

ls o

f ha

bitu

al p

hysi

cal a

ctiv

ity:

estim

ated

line

ar r

egre

ssio

nco

effic

ient

s (b

), s

tand

ard

err

ors

(S

E),

and

p-v

alue

s.

Leve

ls o

fTo

tal c

hole

ster

ol (m

g/d

l)Tr

igly

cerid

e (m

g/d

l)H

DL-

Cho

lest

erol

(mg/

dl)

Tota

l cho

lest

erol

: H

DL-

C r

atio

phy

sica

l act

ivity

a C

oeffi

cien

ts a

dju

sted

for

age

(cat

egor

ical

), ed

ucat

ion,

cig

aret

te s

mok

ing,

alc

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con

sum

ptio

n an

d b

ody

mas

s in

dex

(cat

egor

ical

)b C

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ts a

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sted

for

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egor

ical

), ed

ucat

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alc

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con

sum

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n an

d b

ody

mas

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(cat

egor

ical

)c

Coe

ffici

ents

ad

just

ed f

or a

ge (c

ateg

oric

al),

educ

atio

n an

d b

ody

mas

s in

dex

(cat

egor

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), ed

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ion,

cig

aret

te s

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and

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ass

ind

ex (c

ateg

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βa ±

SE

p-va

lue

βa ±

SE

p-va

lue

βb ±

SE

p-va

lue

βc ±

SE

p-va

lue

Am

ong

men

Low

Ref

eren

ceR

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ence

Ref

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ceR

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ence

Mod

erat

e-0

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4.2

70.

971

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24 ±

13.

480.

364

0.92

± 1

.40

0.51

1-0

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0.1

40.

456

Hig

h3.

73 ±

4.4

80.

405

-30.

92 ±

14.

130.

029

3.42

± 1

.46

0.02

0-0

.29 ±

0.1

40.

043

Tren

d te

st p

-val

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439

0.03

00.

023

0.04

5A

djus

ted

Rb

1.89

%9.

18%

7.62

% 8

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βa ±

SE

p-va

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βd ±

SE

p-va

lue

βa ±

SE

p-va

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p-va

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ong

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35 ±

3.1

60.

001

3.01

± 1

.07

0.00

5-0

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0.0

70.

003

Hig

h-1

.97 ±

3.5

70.

581

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83 ±

4.3

20.

003

4.24

± 1

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0.00

4-0

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0.0

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<0.

001

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0.00

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%14

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Tab

le 3

Od

ds

ratio

(O

R)

and

95

% c

onf

iden

ce in

terv

al (

CI)

of

the

risk

of

dys

lipid

emia

acc

ord

ing

to

leve

ls o

f p

hysi

cal a

ctiv

ity.

Hig

h TC

H =

TC

H ≥

200

mg/

dl;

Hig

h TG

= T

G ≥

150

mg/

dl;

Low

HD

L-C

= H

DL-

C<

40 m

g/d

l in

men

and

HD

L-C

<50

mg/

dl i

n w

omen

; Hig

h TC

H:H

DL-

C r

atio

= T

CH

:HD

L-C

rat

io >

4.5

in m

en a

nd T

CH

:HD

L-C

rat

io >

4 in

wom

ena

Ad

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Ad

just

ed O

Ra

(95%

CI)

Ad

just

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Rb

(95%

CI)

Ad

just

ed O

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(95%

CI)

Ad

just

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Rc

(95%

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Am

ong

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Low

1.00

(Ref

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1.00

(Ref

eren

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1.00

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ce)

Mod

erat

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1.47

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1.60

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85(0

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1.58

)1.

15(0

.74-

1.79

)H

igh

1.28

(0.8

0-2.

06)

0.41

(0.2

4-0.

70)

0.61

(0.3

0-1.

23)

0.76

(0.4

7-1.

22)

Tren

d T

est

p-v

alue

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80.

003

0.17

10.

338

Ad

just

ed O

Rc

(95%

CI)

Ad

just

ed O

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(95%

CI)

Ad

just

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(95%

CI)

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just

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(95%

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Am

ong

wom

enLo

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ence

)1.

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ence

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ence

)M

oder

ate

0.98

(0.7

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0.72

(0.4

7-1.

10)

0.69

(0.4

7-1.

00)

0.72

(0.5

2-1.

00)

Hig

h0.

82(0

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1.21

)0.

43(0

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0.88

)0.

63(0

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1.07

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76(0

.48-

1.19

)Tr

end

tes

t p

-val

ue0.

400

0.01

10.

028

0.07

7

Leve

ls o

fH

igh

TCH

Hig

h TG

Low

HD

L-C

Hig

h TC

H:H

DL-

C R

atio

phy

sica

l act

ivity



mean HDL-C concentrations were also ob-served for women who reported high levels ofphysical activity, when compared with theirless active counterparts (4.24 mg/dl, p =0.004). As shown in Table 2, we also notedthat mean values for TCH:HDL-C ratio de-creased with increasing levels of physical ac-tivity among men and women, respectively(trend test p values both < 0.05).

We next performed logistic regressionanalyses to evaluate risk of dyslipidemia (el-evated TCH, hypertriglyceridemia, reducedHDL-C and elevated TCH:HDL-C ratio) ac-cording to varying levels of physical activity.Results from these analyses are summarizedin Table 3. Overall, there was no clear evi-dence of an association between total cho-lesterol (TCH) concentration and reported lev-els of physical activity among men. When age,education, smoking, alcohol and BMI wereadjusted for, men who reported high levels ofphysical activity where 59% less likely to haveelevated TG (OR=0.41 with 95%CI: 0.24-0.70)compared with men reporting low levels ofactivity. High levels of physical activity wasassociated with a 39% reduction in risk ofhaving low HDL-C concentrations (OR=0.61with 95%CI: 0.30-1.23) and a 24% reductionin r isk of having high TCH:HDL-C ratio(OR=0.76 with 95%CI: 0.47-1.22). However,these associations did not reach statistical sig-nificance.

Risk of dysl ip idemia, part icular lyhypertriglyceridemia and low HDL-C concen-trations, in relation to levels of physical activ-ity were more evident among women. Mod-erate and high levels of physical activity wereassociated with a 28% and 57%, respectively,reduction in risk of hypertriglyceridemia amongwomen (Table 3). Physical activity was alsoinversely related with risk of having low HDL-C concentrations and high TCH:HDL-C ratios.

We also completed analysis stratified byoverweight status to evaluate the extent towhich the association between physical ac-

tivity and dyslipidemia may be modified byBMI. Stratified analysis indicated that asso-ciat ions between physical act iv i ty anddyslipidemia were not modified by BMI sta-tus. Among overweight men, those reportedhigh level of physical activity had a 74% re-duced risk of elevated TG compared to menreporting low level of physical activity (95%CI:0.11-0.59). The corresponding OR for leanmen was 0.59 (95%CI: 0.29-1.23). Stratifiedanalysis of lean and overweight women alsoindicated the absence of effect modificationby BMI. The risk of elevated TG was reducedby 52% in overweight women who reportedhigh level of physical activity compared to theiroverweight counterpart who reported low levelof physical activity (OR=0.48, 95%CI: 0.19-1.17). An association of similar and magni-tude was observed for lean women (OR=0.34,95%CI: 0.10-1.18).

DISCUSSION

Using a detailed physical activity ques-tionnaire, we were able to detect associationsbetween physical activity and serum TG andHDL-C concentrations. Men and women whoreported high level of physical activity wereless likely to have hypertriglyceridemia and lowlevels of HDL-C compared with those report-ing low levels of physical activity. Men whoreported high levels of physical activity hadon average a 3.42 mg/dl higher HDL-C con-centrations when compared to men who re-ported low levels of physical activity. HigherHDL-C concentrations (4.24 mg/dl) were alsoobserved for women who reported high lev-els of physical activity, when compared withtheir less active counterparts. Serum TG con-centrations were 30.92 mg/dl lower in menand 12.83 mg/dl lower in women among thosewho had high levels of activity when comparedwith less active individuals. Results from ourstudy are largely similar to those reported byinvestigators who studied other populations(Durstine et al, 2001; Kraus et al, 2002; Kelley



et al, 2004; Halverstadt et al, 2007).

In a review of the published literature,Durstine et al (2001) reported that most sed-entary persons can experience elevations of2-3 mg/dl in HDL-C and decreases of 8-20mg/dl in TG concentrations by increasing en-ergy expenditure to 1,200-2,200 kcal/week.Halverstadt et al (2007) also reported that 24-week endurance exercise training induced fa-vorable changes in plasma lipoprotein and lipidprofile independent of diet and baseline orchange in body fat. For example, with exer-cise training, serum TG concentrations de-creased significantly (β± SE: -17 ± 3.5 mg/dl,p<0.001). Kraus et al (2002) in their random-ized trial of exercise among sedentary andoverweight men and women with dyslipidemia,reported that the highest amount of weeklyexercise with minimal weight change hadwidespread beneficial effects on the lipopro-tein profile. In a meta-analysis of randomizedcontrolled trial, Kelly et al (2004) reported thataerobic exercise was efficacious for increas-ing HDL-C (95%CI: 0.1, 3.5 mg/dl) and de-creasing TCH (95%CI: -6.9, -1.7), LDL-C(95%CI: -6.5, -2.2) and TG (95%CI: -8.4, -0.1)in women.

Several important limitations must beconsidered when interpreting the results of ourstudy. First, as the study population was com-prised of highly educated middle-aged univer-sity employees, the results may not be gener-alizable to the general Thai population. Sec-ond, we used self-reported physical activityto classify study participants. Therefore, wecannot exclude the possibility that somemisclassification may have occurred. Further,because of this cross-sectional data collec-tion design, we cannot be certain of the tem-poral relation between level of physical activ-ity and risk of dyslipidemia. Inferences con-cerning the protective effect of physical activ-ity and dyslipidemia, however, would be en-hanced with data from prospective studies andrandomized clinical trials.

In conclusion, our study confirms the fa-vorable effects of physical activity on lipid andlipoprotein concentrations among Thai profes-sional and office workers. These are consis-tent with the evidence documenting the car-diovascular health benefits of a physically ac-tive lifestyle.

ACKNOWLEDGEMENTS

This research was supported by theRachadapiseksompoj Faculty of MedicineResearch Fund, Chulalongkorn University.This research was completed while Ms CherellDancy was a research training fellow in theMultidisciplinary International Research Train-ing (MIRT) Program of the University of Wash-ington, School of Public Health and Commu-nity Medicine. The MIRT Program is sup-ported by an award from the National Insti-tutes of Health, National Center on MinorityHealth and Health Dispar i t ies (T37-MD001449). The authors wish to thank thestaff of the Preventive Medicine Clinic, KingChulalongkorn Memorial Hospital in Bangkok,Thailand for their assistance in data collection.

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