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Annals of Clinical & Laboratory Science 32:271-278 (2002)
© 2002 Association of Clinical Scientists

Associations Between Total Body Fat and Serum Lipid Concentrations in Obese Human Adolescents

Jong Weon Choi1, Soo Hwan Pai1 and Soon Ki Kim2
1 Department of Clinical Pathology, 2 Department of Pediatrics Inha University College of Medicine, Inchon, Korea

Address correspondence to Soo Hwan Pai, M.D., Department of Clinical Pathology, Inha University Hospital, 7-206, 3-ga, Shinheung-dong, Jung-gu, Inchon, 400-103, Korea; tel 82 32 890 2502; fax 82 32 890 2529; e-mail shpaimd{at}inha.ac.kr.


   Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
To investigate the relationships between obesity and serum lipid concentrations, we measured eight anthropometric parameters, body mass index (BMI), total body fat (TBF), and serum lipid profiles in 790 apparently healthy adolescents. TBF was assessed using a body fat analyzer. Serum concentrations of triglyceride, total cholesterol, and low- or high-density lipoprotein-cholesterol (LDL-C or HDL-C) were determined by standard enzymatic procedures. There were no significant differences in serum lipid concentrations between obese adolescents (BMI >=95th percentile) and lean adolescents (BMI <5th percentile), nor between overweights (BMI >25 kg/m2) and underweights (BMI <19 kg/m2). However, serum lipid concentrations were significantly higher in males with TBF >37% (TBF >95th percentile) than in males with TBF < 6% (TBF < 5th percentile; p <0.01). Serum lipid concentrations were more strongly correlated with TBF than with BMI. Correlation coefficients between serum lipid concentrations and TBF were higher in males than in females for cholesterol (r = 0.37 vs 0.23), triglycerides (r = 0.29 vs 0.27), HDL-C (r = -0.34 vs 0.12), and LDL-C (r = 0.24 vs 0.15). In short, compared to BMI, TBF reflects serum lipid concentrations more closely. During adolescence, the association between TBF and serum lipid concentrations is stronger in males than in females.

(received 24 January 2002; accepted 1 February 2002)

Keywords: total body fat, body mass index, serum lipid concentration, adolescent obesity


   Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
Obesity is a condition of abnormally increased body fat, resulting from increased energy intake relative to energy expenditure. The prevalence of obesity is rapidly rising worldwide, and obesity is a leading nutrition-related disorder. Overweight adolescents have increased risk of hypertension, heart disease, and diabetes mellitus [1]. Longitudinal studies indicate that overweight and fatness during adolescence may predict later increases in health risks and adult mortality [2–4]. Obese people with body mass index (BMI) greater than 30 kg/m2 have a greater risk of dying earlier than the non-obese [5]. When body weight is >20% above average, mortality rises 20% in men and 10% in women [6].

There have been many attempts to estimate body fat mass as an obesity index, because adipose tissue is the major site for fat storage and contains >90% of total energy stores [7]. Subcutaneous fat mass can be measured as a sum of 10 skinfolds, and visceral fat can be assessed as an area by computed tomography [5]. Body fat mass can also be determined by hydrodensitometry [8]. However, none of these methods can establish precisely the composition of the living body.

Recently, a bioelectric impedance device has been introduced to estimate the percentage of total body fat (TBF) mass. This device differs from impedance systems that use surface electrodes, since the subjects stand bare-footed on a metal soleplate that contains the electrodes, so that impedance is measured through the legs and lower trunk [9,10].

BMI has been used routinely to screen for overweight subjects; hence most previous epidemiologic studies have been based on BMI, skinfold thickness, or waist circumference [11,12]. Some investigators have reported the correlations between BMI and plasma lipid levels in adults [13–15]. However, few studies have closely examined relationships between TBF and serum lipid concentrations, especially as compared to BMI in healthy adolescents. In a previous study, we demonstrated that severe iron deficiency anemia is attended by decreased concentrations of serum total cholesterol and triglycerides [16]. In our current study, we measured TBF using a bioelectric impedance device, BMI, and eight anthropometric parameters in healthy adolescents who had no evidence of severe anemia, to ascertain which index most accurately reflects serum lipid concentrations in obese humans.


   Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Serum lipid profiles, including total cholesterol, triglycerides, high density lipoprotein cholesterol (HDL-C), and low density lipoprotein cholesterol (LDL-C), were performed in 790 apparently healthy adolescents (middle- or high-school students aged 14–19 yr). Because severe anemia or iron supplementation may affect serum lipid concentrations [16], we excluded 12 subjects from this study: 6 had severe anemia (hemoglobin <8.0 g/dl), 4 had received iron supplementation, and 2 had undergone surgical operations. This study was approved by the Ethical Committee of Inha University Hospital, and informed consent was obtained from all subjects.

Eight anthropometric parameters and blood pressure were measured in all subjects. The anthropometric indices included body weight; height; circumference of upper chest, upper arm, waist, and hip; as well as subscapular and triceps skinfold thickness measured by a caliper. Body adiposity was assessed using a leg-to-leg bioelectric impedance device (Tanita body fat analyzer, model TBF-611, Tanita, Tokyo, Japan), which enables simultaneous measurements of body weight, impedance, fat-free mass, total body water, and fat percentage, while the subject stands on the stainless steel electrode. BMI and waist to hip circumference ratio (WHR) were computed: BMI was determined as body weight in kg divided by the square of the height in meters (kg/m2). The normal range of BMI is defined as 19.0– 24.9 kg/m2, overweight as a BMI of 25.0 to 29.9 kg/m2, and obesity as BMI >=30.0 kg/m2 [17]. The subjects were divided into 3 groups: underweight (BMI <19.0 kg/m2, n = 130), healthy weight (BMI from 19.0 to 24.9 kg/m2, n = 536), and overweight (BMI >=25.0 kg/m2, n = 124).

To compare serum lipid concentrations in extremely lean subjects versus extremely obese subjects, we selected the subjects >95th percentile and <5th percentile for BMI and TBF, respectively: <5th percentile (BMI <16.0 kg/m2 or TBF <6.0% in males; BMI <16.0 kg/m2 or TBF <9.0% in females) and greater than 95th percentile (BMI >31.0 kg/m2 or TBF >37.0% in males; BMI >32.0 kg/m2 or TBF >56.0% in females).

Venous blood (7 ml) was drawn into evacuated, serum separator tubes after 12 hr fasting. Complete blood cell count was performed on EDTA-anticoagulated blood using an electronic counter (SE 9000, Sysmex, Kobe, Japan). All lipid profiles were measured with an automatic chemical analyzer (Hitachi 747, Hitachi, Tokyo, Japan) within 4 hr after collection. Serum triglycerides, total cholesterol, HDL-C, and LDL-C concentrations were analyzed by enzymatic colorimetric methods using triglyceride GPO-PAP reagents (Roche Diagnostics GmbH, Mannheim, Germany), SICDIA L T-CHO reagents (Eiken Chemical Industries, Tokyo, Japan), Cholestest-LDL reagents (Daiichi Chemicals, Tokyo, Japan), and Cholestest-HDL reagents (Daiichi Chemicals), respectively [18–21].

Data analysis was performed with SAS statistical software (version 6.12; SAS Institute Inc, Cary, NC, USA). The Mann-Whitney U-test was used to assess the statistical differences of lipid concentrations between groups. The correlations of TBF and BMI versus serum lipid concentrations were assessed by Pearson correlation coefficients. All p values < 0.01 were considered statistically significant.


   Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
The clinical features and laboratory data of the subjects are summarized in Table 1Go. Of the 790 adolescents, high school students comprised 49.2% of the total. There were no significant differences in anthropometric parameters and serum lipid concentrations between middle- and high-school students. Table 2Go demonstrates serum lipid concentrations of the underweights and the overweights based on BMI. No significant differences were observed in serum lipid concentrations between the underweights (BMI <19 kg/m2) and the overweights (BMI >=25 kg/m2) in both males and females.


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  		Table 1. Clinical parameters and laboratory data (mean ± SD) of the subjects included in this study
 

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  		Table 2. Serum lipid concentrations (mean ± SD and [median]) based on BMI (for abbreviations see Table 1Go)
 
Changes in serum lipid concentrations with the corresponding alteration of TBF are illustrated in Figs. 1Go and 2Go. In females, serum concentrations of all lipid profiles increased gradually as TBF was elevated. In males, serum concentrations of HDL-C decreased as TBF increased. As shown in Table 3Go, boys with TBF >20% and girls with TBF >=30% showed significantly high values in most anthropometric parameters, compared to boys with TBF <20% and girls with TBF <30%. There were no significant differences in serum lipid levels or blood pressure between the male subjects with TBF <20% and TBF >=20% or between the female subjects with TBF <30% and TBF >=30%.



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  		Fig. 1. Changes in serum lipid concentrations in 387 adolescent males. As total body fat increases, mean concentrations of total cholesterol (TC, open circles), triglyceride (TG, closed circles), and LDL-cholesterol (LDL-C, open triangles) are increased, but those of HDL-cholesterol (HDL-C, closed triangles) are decreased.

 


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  		Fig. 2. Changes in serum lipid concentrations in 403 adolescent females. Serum concentrations of all lipid profiles, such as total cholesterol (TC, open circles), triglyceride (TG, closed circles), HDL-cholesterol (HDL-C, closed triangles), and LDL-cholesterol (LDL-C, open triangles) are increased as the total body fat is elevated.

 

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  		Table 3. Anthropometric parameters and serum lipid concentrations (mean ± SD) based on total body fat (TBF) (for abbreviations, see Table 1Go)
 
On the other hand, we selected the extremely lean and extremely obese subjects that correspond to <5th percentile and >95th percentile for BMI and TBF, respectively, and compared the serum lipid concentrations between the two groups. There were no significant differences in serum lipid concentrations between the subjects with BMI >95th percentile and BMI <5th percentile. However, obese boys with TBF >95th percentile (TBF >37%, n = 19) did show significantly higher concentrations in all lipid profiles than did the boys with TBF <5th percentile (TBF <6%, n = 19; p <0.01). In particular, mean triglyceride concentrations in extremely lean boys averaged 67.6 ± 30.1 mg/dl, which was significantly lower than in extremely obese boys (150.5 ± 43.9 mg/dl, p <0.01). On the other hand, obese girls with TBF >95th percentile (TBF >56%, n = 20) had an elevation in only serum cholesterol levels, compared to girls with TBF <5th percentile (TBF <9%, n = 20; p <0.01) (Table 4Go).


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  		Table 4. Serum lipid concentrations in extremely lean and extremely obese adolescents (for abbreviations see Table 1Go)
 
Correlation coefficients of TBF and BMI versus serum lipid concentrations in 124 overweight subjects (BMI >=25 kg/m2) are summarized in Table 5Go. Serum lipid concentrations were more strongly correlated with TBF than with BMI. Correlations coefficients between serum lipid concentrations and TBF were higher in males than females for serum total cholesterol (r = 0.37 vs 0.23), triglycerides (r = 0.29 vs 0.27), HDL-C (r = -0.34 vs 0.12), and LDL-C (r = 0.24 vs 0.15).


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  		Table 5. Correlations of TBF and BMI vs serum lipid concentrations in 124 adolescents with BMI >=25 kg/m2
 

   Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
In this study, we investigated the changes in serum concentrations of triglycerides, total cholesterol, HDL-cholesterol, and LDL-cholesterol in adolescents in relationship to alterations in TBF and BMI. We found that serum lipid concentrations are more closely correlated with TBF than with BMI, and that these associations are stronger in males than females during adolescence. Our results are in partial agreement with a previous report of Hu et al [22], who found that in men, BMI was positively correlated with triglyceride and negatively correlated with HDL-cholesterol. Correlations between anthropometric parameters and lipid levels or blood pressure have varied in different studies. For example, Flodmark et al [23] found that BMI was significantly correlated with serum triglycerides and diastolic blood pressure. Anderson et al [24] reported that in adult men and women, the anthropometric measurements were inversely associated with levels of serum HDL cholesterol.

In our study, serum lipid concentrations showed stronger correlations in males than in females not only with BMI but also with TBF. These results suggest that association between TBF and serum lipid concentrations is closer in males than females during adolescence. Contrary to our results, Margolis et al [25] found that correlations between lipid levels and BMI were stronger in women than in men for serum cholesterol, LDL-C, triglycerides, and the ratio of cholesterol/HDL-C. These discrepancies may have derived from the differences of age and nutritional status in the respective populations. Margolis et al [25] investigated lipid levels in subjects with an average age of 40 yr, whereas we investigated obese adolescents aged 14–19 yr. We also determined the correlation coefficients of TBF and BMI versus serum lipid concentrations. Correlation coefficients between TBF and lipid profiles were higher than those for BMI in both males and females, suggesting that TBF is more closely associated with serum lipid concentrations than BMI, at least in adolescents.

In this study, there were no significant differences in serum lipid concentrations between overweights (BMI >=25 kg/m2) and underweights (BMI <19 kg/m2). Also, no significant differences were observed in serum lipid concentrations and blood pressure between the males with TBF <20% versus TBF >=20% or between the females with TBF <30% versus TBF >=30%, although most anthropometric parameters showed significant differences at these cutoff levels. We selected the extremely obese and extremely lean subjects who correspond to >95th percentile and <5th percentile of populations for BMI and TBF, respectively. We failed to find significant differences in serum lipid concentrations between the two groups, even after we selected only the adolescents with BMI >95th percentile and BMI <5th percentile.

However, when we compared the subjects on the basis of TBF, extremely obese boys with TBF >95th percentile (TBF >37%) showed significantly higher concentrations in all lipid profiles than extremely lean boys with TBF <5th percentile. Extremely obese girls with TBF >95th percentile (TBF >56%) showed significantly high concentrations only of serum cholesterol, compared to extremely lean girls with TBF <5th percentile. These results suggest that TBF may affect serum lipid concentrations, but the contribution of TBF is evident only when the TBF is extremely increased (>37% in males or >56% in females).

In conclusion, relatively high correlations between TBF and serum lipid concentrations were observed in boys, compared to girls, suggesting that associations between TBF and serum lipid concentrations are stronger in males than in females during adolescence.


   References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Lean ME. Pathophysiology of obesity. Proc Nutr Soc 2000;59:331–336.[Medline]
  2. Johnson AL, Cornoni JC, Cassel JC, Tyroler HA, Heyden S, Hames CG. Influence of race, sex and weight on blood pressure behavior in young adults. Am J Cardiol 1975;35:523–530.[Medline]
  3. Must A, Jacques PF, Dallal GE, Bajema CJ, Dietz WH. Long-term morbidity and mortality of overweight adolescents. N Engl J Med 1992;327: 1350–1355.[Medline]
  4. Nieto FJ, Szklo M, Comstock GW. Childhood weight and growth rate as predictors of adult mortality. Am J Epidemiol 1992;136:201–213.[Abstract/Free Full Text]
  5. Ashwell M. Obesity in men and women. Int J Obes Relat Metab Disord 1994;18(Suppl 1):1–7.
  6. Bray GA. Overweight is risking fate: definition, classification, prevalence, and risks. Ann N Y Acad Sci 1987;499:14–28.[Medline]
  7. Bray GA. Obesity: basic considerations and clinical approaches. Dis Mon 1989;35:449–537.[Medline]
  8. Maynard LM, Wisemandle W, Roche AF, Chumlea WC, Guo SS, Siervogel RM. Childhood body composition in relation to body mass index. Pediatrics 2001;107:344–350.[Abstract/Free Full Text]
  9. Jebb SA, Cole TJ, Doman D, Murgatroyd PR, Prentice AM. Evaluation of the novel Tanita body-fat analyzer to measure body composition by comparison with a four-compartment model. Br J Nutr 2000;83:115–122.[Medline]
  10. Jartti L, Hakanen M, Paakkunainen U, Raittinen P, Ronnemaa T. Comparison of hand-to-leg and leg-to-leg bioelectric impedance devices in the assessment of body adiposity in prepubertal children. The STRIP study. Acta Paediatr 2000;89:781–786.[Medline]
  11. Himes JH, Dietz WH. Guidelines for overweight in adolescent preventive services: recommendations from an expert committee. Am J Clin Nutr 1994;59: 307–316.[Abstract/Free Full Text]
  12. Kuczmarski RJ, Flegal KM. Criteria for definition of overweight in transition: background and recommendations for the United States. Am J Clin Nutr 2000;72:1074–1081.[Abstract/Free Full Text]
  13. DiPietro L, Katz LD, Nadel ER. Excess abdominal adiposity remains correlated with altered lipid concentrations in healthy older women. Int J Obes Relat Metab Disord 1999;23:432–436.[Medline]
  14. Soler JT, Folsom AR, Kushi LH, Prineas RJ, Seal US. Association of body fat distribution with plasma lipids, lipoproteins, apolipoproteins AI and B in postmenopausal women. J Clin Epidemiol 1988;41: 1075–1081.[Medline]
  15. Haarbo J, Hassager C, Riis BJ, Christiansen C. Relation of body fat distribution to serum lipids and lipoprotein in elderly women. Atherosclerosis 1989; 80:57–62.[Medline]
  16. Choi JW, Kim SK, Pai SH. Changes in serum lipid concentrations during iron depletion and after iron supplementation. Ann Clin Lab Sci 2001;31:151–156.[Abstract/Free Full Text]
  17. Pi-Sunyer FX. Obesity: criteria and classification. Proc Nutr Soc 2000;59:505–509.[Medline]
  18. Allain CC, Poon LS, Chan CS, Richmond W, Fu PC. Enzymatic determination of total serum cholesterol. Clin Chem 1974;20:470–475.[Abstract]
  19. Friedwald WT, Levy RI, Fredrickson DS. Estimation of the concentration of low-density lipoprotein cholesterol in plasma without use of the preparative ultracentrifuge. Clin Chem 1972;18:499–502.[Abstract/Free Full Text]
  20. Olson RE. A critique of the report of the National Institute of Health expert panel on detection, evaluation, and treatment of high blood cholesterol. Arch Intern Med 1989;149:1501–1503.[Abstract/Free Full Text]
  21. Gordon T, Castelli WP, Hjortland MC, Kanel WB, Dawber TR. High density lipoprotein as a protective factor against coronary heart disease. Am J Med 1977;62:707–714.[Medline]
  22. Hu D, Hannah J, Gray RS, Jablonski KA, Henderson JA, Robbins DC, Lee ET, Welty TK, Howard BV. Ects of obesity and body fat distribution on lipids and lipoproteins in nondiabetic American Indians: the Strong Heart Study. Obes Res 2000;8: 411–421.[Medline]
  23. Flodmark CE, Sveger T, Nilsson-Ehle P. Waist measurement correlates to a potentially atherogenic lipoprotein profile in obese 12–14-year-old children. Acta Paediatr 1994;83:941–945.[Medline]
  24. Anderson AJ, Sobocinski KA, Freedman DS, Barboriak JJ, Rimm AA, Gruchow HW. Body fat distribution, plasma lipids, and lipoproteins. Arteriosclerosis 1988;8:88–94.[Abstract/Free Full Text]
  25. Margolis CF, Sprecher DL, Simbartl LA, Campaigne BN. Male-female differences in the relationship between obesity and lipids/lipoproteins. Int J Obes Relat Metab Disord 1996;20:784–790.[Medline]



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