Trend and risk factors foR obesity - PowerPoint Presentation

Slide1

Trend and risk factors foR obesity among HIV positive Nigerians on antiretroviral therapy.

Ezechi Lilian O.

BSc, MSc, MEd

Department of Home Economics

School of Vocational Education

Federal College of Education(Tech), Lagos Nigeria Slide2

Background With the improved access to life saving antiretroviral drugs , HIV-infected persons are living longer and experiencing lower rates of acquired immunodeficiency syndrome (AIDS)-related wasting syndrome (Kitahata et al., 2009)A large number of published works continue to note a growing number of overweight and obese HIV positive individuals while on treatment, raising the possibility that HIV and/or its treatment may be associated with obesity (Crum-Cianflone et al., 2010; Parikh et al., 2007).Slide3

Background..2 Unfortunately, the reported evidence are mainly from settings outside sub Saharan Africa, with low HIV burden (Wanke et al., 2000; Liu et al., 2006). However, the available studies do provide useful insights into a potentially emerging problem of obesity,. Another potential challenge is the paucity of studies that evaluated the risk factor for the emergence of obesity among HIV positive individual in HIV high burden countries (Crum-Cianflone et al., 2010; Liu et

al., 2006). Slide4

Background..3Obesity is a notable risk factor for cardiovascular diseases and sudden deaths both in the general population (Crum-Cianflone et al., 2008; Ilo et al., 2011) and stable HIV population (Palella and Delaney, 1998). An urgent need to address the challenge of obesity in order not to loss the gains made with the introduction of antiretroviral drugs. First step to addressing the obesity challenge is to determine the burden and the risk factors for the development of obesity among stable HIV positive population. Slide5

Study ObjectiveTo determine the trend and risk factors for obesity among a cohort of HIV infected adults on antiretroviral therapy. Slide6

MethodStudy design Cohort review of prospectively obtained data of adult HIV positive Nigerian men and women enrolled in an ongoing observational longitudinal study to determine long term efficacy of Nigerian national antiretroviral treatment programme. The enrolment into the programme started in 2002 and still on-going. Study setting HIV treatment centre, Nigerian Institute of Medical Research, Lagos. A Federal Government of Nigeria HIV Treatment centre. Over 23,000 patients enlisted in the programme. Slide7

Method..2Study Population Adult HIV positive Nigerians enrolled in a longitudinal study to evaluate the treatment outcome of Nigerian national HIV treatment programme. Adult Nigerian commenced on antiretroviral drug , between January 2004 and December 2009 and followed up for five years were eligible for inclusion into this study. Patients before enrolment into the programme signed an informed consent for use of their de-identified data for research. Slide8

Data managementInformation on age at enrolment, sex, height, weight, marital status, educational status, WHO disease stage, oppourtunisitic infection, ARV status, type of ARV drug regimen, CD4 count, haemoglobin, viral load, cholesterol, LDL and HDL at enrolment, 12 , 24, 36,48, and 60 monthly visits were extracted for each patient from the programme database . Extracted data were exported and analysed with SPSS for windows version 20.0. Obesity was classified using patients BMI Slide9

Data management..2 Univariate analysis was first performed to identify factors associated with obesity. Multivariate logistic regression was further used to identify independent risk factors for obesity, while controlling for potential confounding variables. In the analysis, the comparison group was non-obese adult HIV positive. P < 0.05 was considered to be statistically significant. Odds Ratios (OR) and 95% Confidence Intervals (CI) for the OR were also calculated.Slide10

Ethical IssuesApproval for the study was obtained from the Institutional Review Board, Nigerian Institute of Medical Research, Lagos Nigeria. At enrolment into the treatment programme patients are required to sign an informed consents for the use of their de-identified data for research. However those who declined consent for the use of their data for research are provided care but excluded for research.Slide11

ResultsA total of 12,585 individuals were enrolled into the programme between Jul. 2004 and Dec. 2009 and followed up for 5 years. However only 8819 (70.1%) met the specific study eligible criteria and were used for the analysis. Slide12

Baseline sociodemographic characteristic of the 8,819 HIV positive study participants Characteristics Number of Participants (%)Age (years)

Less than 30

30 – 49

50 and above

Range

Mean

Sex

Female

Male

Marital status

Married

Single

Divorced/Separated

Widowed

Education

Less than secondary (<12 years)

Secondary and above (≥12 years)

Identifiable risk for HIV transmission

Heterosexual

Intravenous drug use

Men having sex with men

Mother to child

Blood Transfusion

Unknown

WHO disease stage

1 and 2

3 and

4

2425(27.5)

5714(64.8)

679(7.7)

16 – 82

35.5 ± 7.1

5660(64.2)

3159(35.8)

5102(57.9)

2347(26.6)

486(5.5)

883(10.0)

2351(26.7)

6468(73.3)

7263(82.4)

12(0.1)

56(0.6)

7(0.08)

342(3.9)

1138(12.9)

2893(32.8)

5926(67.2)

 Slide13

Distribution of baseline BMI by year of enrolment (2004-2009) 

BMI

category

Year of enrolment and number of patients enrolled

2004

n = 383(%)

2005

n = 1256(%)

2006

n = 1518(%)

2007

n = 1914(%)

2008

n = 1993(%)

2009

n=1755(%)

Total

n= 8819(%)

Wasted (< 18.5 )

63(16.4)

200(15.9)

234(15.4)

308(16.1)

315(15.8)

274(15.6)

1394(15.8)

Underweight

(

18.5-19.9)

55(14.3)

165(13.1)

203(13.4)

234(12.2)

239(12.0)

244(13.9)

1140(12.7)

Normal (20-24.9)

168(43.9)

515(41.0)

525(44.5)

869(45.4)

903(45.3)

774(44.1)

3754(44.4)

Overweight

(

25-30)

71(18.6)

252(20.1)

294(19.4)

350(18.3)

372(19.3)

325(18.5)

1664(19.7)

Obesity (>30)

27(7.1)

87(6.9)

111(7.3)

153(8.0)

151(7.6)

139(7.9)

668(7.4)Slide14

Five year trend in prevalence of obesity among the cohortSlide15

Risk factors for obesity among 8819 HIV positive Nigerian on antiretroviral therapy.Characteristics  Univariate

Multivariate

OR [95% CI]

P value

OR [95% CI]

P value

Age (years)

Less than 35

≥ 35

Sex

Female

Male

Marital status

Married

Unmarried

Education status

Less than secondary

Secondary and above

Social class

Low

Middle

Upper

Baseline BMI

< 20

≥

20

1.33(1.13 – 1.56)

1.0

2.09(1.75 – 2.50)

1.0

1.0

0.76(0.65 - 0.90)

1.31(1.07 – 1.60

1.0

2.11(0.13 – 8.32)

1.0

0.63 (0.22 – 1.65)

2.4(1.5 -2.9

)

1.0

0.001

0.000

0.001

0.01

0.03

0.09

0.01

1.01(0.76 – 2.01)

1.0

2.2(1.81-2.67)

1.0

0.54(0.43 – 1.23)

1.5(0.84 – 2.56)

1.0

1.9(0.87 – 6.73)

1.0

0.35(0.19 – 3.21)

1.9(1.3-2.2)

1.0

0.06

0.007

0.09

0.21

0.34

0.63

0.02Slide16

Risk factors for obesity among 8819 HIV positive Nigerian on antiretroviral therapy…2Characteristics  Univariate

Multivariate

OR [95% CI]

P value

OR [95% CI]

P value

Oppourtunisitic

infection

Yes

No

Type of ARV drugs

d4T based regimen

AZT based Regimen

CD4 count

<350

≥ 350

Haemoglobin

<10

≥ 10

Viral load

<100.000

≥100,000

Cholesterol/HDL ratio

<4.0

≥4.0

1.0

0.72(0.49 – 1.07)

0.75(0.41 – 1.36)

1.0

1.44(1.18 – 1.76)

1.0

1.0

1.28(1.08 – 1.53)

1.0

1.27(1.08 – 1.50)

1.0

1.43(1.09 – 1.86)

 0.09

0.31

0.0002

0.04

0.003

0.01

1.0

0.51(0.72 – 2.32

)

0.63(0.53

– 2.22)

1.0

2.51(2.13 – 3.09)

1.0

1.0

1.49(0.95 – 2.34)

1.0

1.33(0.98-2.76)

1.0

2.13(0.73 – 3.17

0.15

0.54

0.006

0.09

0.63

0.67Slide17

DiscussionWe found a low prevalence of obesity at enrolment with a significant progressive increase after starting antireoviral therapy. Proportion of obese patients increased from a baseline figure of 7.4% to 26.5% at the end of 5th year of follow up. Although there is a reported increase in obesity among the general population in Nigeria (Olatunbosun et al., 2011; Ilo et al., 2011), the reported 26.5% after 5 years of treatment is not likely to be a reflection of the growing obesity epidemic in the country’s general population which is reportedly in the range of 3.5-8.5% across the nation (Olatunbosun

et

al.,

2011;

Ilo

et

al., 2011).Slide18

Discussion..2The improved access to antiretroviral therapy has resulted in lower rates of AIDS related wasting syndrome and HIV infected persons becoming obese at a rate similar to that of the general population and in addition to the excess weight gain from medical comorbidities common among HIV positive individuals (Palella and Delaney, 1998; Rickerts et al., 2000).Our study also demonstrated that the development of obesity is associated with low baseline BMI (aOR: 1.9; 95% CI: 1.3-2.2), female gender (aOR: 2.2; 95% CI: 1.8 -2.7) and baseline CD4 count less than 350 cells/mm3 (aOR: 2.5; 95% CI: 2.1 -3.1). Slide19

Discussion..3Low baseline BMI was found to be associated with obesity among our cohort. Although the explanation for this finding is not immediately obvious, the underweight and wasted patients at the time of enrolment had more advanced disease and may have become healthier and gained weight over time with recovery and clearance of opportunistic infections. Patients in this category also tend to adhere better to their drugs and hence faster recovery (Ekama et al., 2012). Another possible explanation for the observed association of low baseline BMI and obesity may be that the stigma associated with wasting in AIDS patients encourage eating to gain weight in an attempt to obscure the diagnosis of AIDs (Shor-Posner et al., 2000). Slide20

Discussion..4The observed association between female gender and obesity in this study is in agreement with previous studies in both the general and HIV infected population (Olatunbosun et al., 2011; Ilo et al., 2011; Boodram et al., 2009). Also previous studies in our environment reported higher rates of obesity in women compared to men (Olatunbosun et al., 2011; Ilo et al., 2011).Boodram and colleagues reported higher rates of overweight and obesity among an all HIV positive female cohort compared to studies that include men only or both sexes

.(

Boodram

et

al., 2009)

The

findings in this study and others

that

females

are

at greater risk for obesity

underscores the need to

develope

female

centered

obesity

prevention interventions (

Boodram

et

al., 2009). Slide21

Discussion..5The observed association between low baseline CD4 count < 350 and obesity is in agreement with previous studies showing a correlation between immune reconstitution and increased gain in weight (Palenicek et al., 1995; Jones et al., 2003). Patients with low Cd4 count are at advanced disease stage and are more likely to adhere better to their treatment enhancing their recovery in a shorter time (Ekama et al., 2012). The stigma associated with wasting in patients with advance disease may also encourage

eating to

recover

the lost body weight. Slide22

ConclusionThe prevalence of obesity and overweight is high among HIV-infected persons on antiretroviral therapy. Female patients , those with low baseline BMI and CD4 count < 350 are particularly at risk of becoming obese during antiretroviral therapy. Programme targeted at prevention of obesity and its sequel among HIV infected population should be integrated into routine HIV care with special focus on women and those with advanced disease. Slide23

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