Body morphology differentially predicts coronary calcium

BMI is not independently associated with coronary artery calcification in a large single‐center CT cohort

Objective

Obesity is associated with cardiovascular disease (CVD) and CVD mortality. However, previous reports showed a paradoxical protective effect in patients with known CVD referred as "obesity paradox". Therefore, the aim of the present study was to investigate the association of body mass index (BMI) with coronary artery calcification (CAC) in a large outpatient cardiac CT cohort.

Methods

4.079 patients who underwent cardiac CT between December 2007-May 2014 were analyzed. BMI and clinical risk factors (current smoking, diabetes mellitus type 2, family history, systolic blood pressure, lipid spectrum) were assessed. Missing values were imputed using multiple imputation. CAC extent was categorized as absent (0), mild (>0-100), moderate (>100-400) and severe (>400).

Results

Multivariable multinomial logistic regression analysis, including all risk factors as independent variables, showed no association between BMI and CAC. Using absence of calcification as reference category, the odds ratios per unit increase in BMI were 1.01 for mild; 1.02 for moderate; and 1.00 for severe CAC (p-values ≥0.103).

Conclusions

No statistically significant association was observed between BMI and CAC after adjustment for other risk factors.

Relation of the quantity of coronary calcium to the quantity of aortic calcium determined from radiographs at necropsy

Described herein are radiographs of the heart and aorta at necropsy after "cleaning" these structures of extraneous tissue. As a consequence, the quantity of calcium is far more discernible than by computed tomography or magnetic resonance or ultrasonic imaging during life or before extraneous tissues are removed at necropsy. We illustrate these radiographic images at necropsy in three patients to show that the relative amount of calcific deposits in the coronary arteries and aorta may be subjectively similar or one of these structures may have far more calcium in the arterial walls than the other. The reasons for these differences are unclear.

Investigation of relation between visceral and subcutaneous abdominal fat volumes and calcified aortic plaques via multislice computed tomography

OBJECTIVE

The present study investigated effect of subcutaneous fat volume and abdominal visceral fat volume on aortic atherosclerosis via multislice computed tomography.

MATERIALS AND METHODS

The present study comprised 424 subjects who underwent non-contrast-enhanced abdominal CT in our clinic between June 2012 and June 2013. Using dedicated software visceral fat volume was calculated for each individual and then subcutaneous fat volume was calculated by subtracting visceral fat volume from total fat volume. By dividing visceral fat volume/subcutaneous fat volume participants were assigned to three groups according to their mean visceral fat volume/subcutaneous fat volume: Group 1 consisted of subjects with visceral fat volume/subcutaneous fat volume lower than 0.48 (Group 1 < 0.48); Group 2 consisted of subjects with visceral fat volume/subcutaneous fat volume equal to or higher than 0.48 and lower than 0.69 (0.48 ≤ Group 2 < 0.69); and Group 3 consisted of subjects with visceral fat volume/subcutaneous fat volume equal to or higher than 0.69 (Group 3 ≥ 0.69).

RESULTS

The mean abdominal aortic calcium scores according to Agatston scoring (au) were 136.8 ± 418.7 au in Group 1, 179.9 ± 463 au in Group 2 and 212.2 ± 486.9 in Group 3, respectively.

CONCLUSIONS

We have demonstrated a significant correlation between visceral fat volume and abdominal aorta atherosclerosis, while there was absence of significant correlation between subcutaneous fat volume and abdominal atherosclerosis.

Atherosclerosis burden in patients with acute chest pain: obesity paradox

Obesity paradox has been described in various populations of coronary artery disease, mainly asymptomatic subjects. However, relationship between obesity and coronary artery calcification detected by cardiac CT in symptomatic patients has rarely been demonstrated. This study seeks to investigate whether the paradoxical relationship between obesity and coronary artery calcification exists in patients with acute chest pain. A final cohort of 1030 chest pain patients presenting at our emergency department who underwent coronary evaluation by multidetector cardiac CT were examined. With absent-to-mild coronary calcification (CAC score < 100) as a referent, multivariable analysis showed that presence of obesity (OR 0.564; 95% CI 0.395, 0.806; P 0.002), body mass index (OR 0.945; 95% CI 0.920, 0.971; P < 0.001), body weight (OR 0.987; 95% CI 0.979, 0.995; P 0.001), and body surface area (OR 0.582; 95% CI 0.369, 0.920; P 0.020) were inversely associated with moderate-to-severe coronary calcification (CAC score ≥ 100). This study extends the concept of obesity paradox to symptomatic patients undergoing coronary artery calcium score assessment. However, biological explanation(s) of this paradox remains unanswered.

Coronary artery calcification is inversely related to body morphology in patients with significant coronary artery disease: a three-dimensional intravascular ultrasound study

AIMS

Emerging data have indicated unexpected complexity in the regulation of vascular and bone calcification. In particular, several recent studies have challenged the concept of a universally positive relationship between body morphology [weight, height, body mass index (BMI), body surface area (BSA)] and the extent of vascular calcification. We sought to clarify these discrepancies and investigated the relationship between index lesion coronary artery calcification (CAC) and body morphology in patients undergoing percutaneous coronary intervention (PCI) using three-dimensional intravascular ultrasound (IVUS).

METHODS AND RESULTS

We analysed CAC in patients who underwent PCI with pre-intervention IVUS imaging. The main outcome measure was the calcium index (CalcIndex); a three-dimensional IVUS-derived measure of total calcification per obstructive coronary lesion. A total of 346 patients (65.3 ± 10.6 years; 29.5% females) underwent PCI with IVUS-based CAC assessment. CalcIndex was categorized as zero-low (0-0.1399; n = 152) or intermediate-high (0.1400-1.2541; n = 194). All measures of body morphology were lower in patients with intermediate-high CalcIndex (height, P = 0.024; weight, P = 0.008; BMI, P = 0.064; BSA, P = 0.005). In adjusted multivariable models, weight and BSA were independent inverse predictors of intermediate-high CalcIndex [weight: odds ratio (OR) 0.986, P = 0.017; BSA: OR 0.323, P = 0.012] while CalcIndex also trended towards an inverse association with both height (P = 0.068) and BMI (P = 0.064). These independent inverse associations were consistent across multiple clinical subgroups, including stratification by age, race, gender, diabetes, and renal impairment.

CONCLUSION

Using three-dimensional IVUS to assess vascular calcification, these data confirm an independent, inverse relationship between body size and index lesion CAC in patients with obstructive coronary artery disease.

Fasting glucose, obesity, and coronary artery calcification in community-based people without diabetes

OBJECTIVE

Our objective was to assess whether impaired fasting glucose (IFG) and obesity are independently related to coronary artery calcification (CAC) in a community-based population.

RESEARCH DESIGN AND METHODS

We assessed CAC using multidetector computed tomography in 3,054 Framingham Heart Study participants (mean [SD] age was 50 [10] years, 49% were women, 29% had IFG, and 25% were obese) free from known vascular disease or diabetes. We tested the hypothesis that IFG (5.6-6.9 mmol/L) and obesity (BMI ≥30 kg/m(2)) were independently associated with high CAC (>90th percentile for age and sex) after adjusting for hypertension, lipids, smoking, and medication.

RESULTS

High CAC was significantly related to IFG in an age- and sex-adjusted model (odds ratio 1.4 [95% CI 1.1-1.7], P = 0.002; referent: normal fasting glucose) and after further adjustment for obesity (1.3 [1.0-1.6], P = 0.045). However, IFG was not associated with high CAC in multivariable-adjusted models before (1.2 [0.9-1.4], P = 0.20) or after adjustment for obesity. Obesity was associated with high CAC in age- and sex-adjusted models (1.6 [1.3-2.0], P < 0.001) and in multivariable models that included IFG (1.4 [1.1-1.7], P = 0.005). Multivariable-adjusted spline regression models suggested nonlinear relationships linking high CAC with BMI (J-shaped), waist circumference (J-shaped), and fasting glucose.

CONCLUSIONS

In this community-based cohort, CAC was associated with obesity, but not IFG, after adjusting for important confounders. With the increasing worldwide prevalence of obesity and nondiabetic hyperglycemia, these data underscore the importance of obesity in the pathogenesis of CAC.

Influence of patients' coronary artery calcium on subsequent medication use patterns

OBJECTIVES

To determine whether information on the presence and extent of coronary artery calcium (CAC) is associated with the likelihood of physicians' prescribing preventive therapies.

METHOD

In a longitudinal design, asymptomatic participants (N=510) were evaluated by computed tomography for CAC. Changes to medications were at the discretion of the patient's primary care provider, who received the CT report.

RESULTS

In multivariable analysis, the likelihood of patients reporting that their primary care physician prescribed preventive therapies was significantly associated with the presence and extent of CAC.

CONCLUSIONS

This study suggests that physicians' prescribing practices are influenced by patients' CAC scores obtained via CT.

Inverse relationship between body mass index and coronary artery calcification in patients with clinically significant coronary lesions

AIMS

Mounting data support a 'calcification paradox', whereby reduced bone mineral density is associated with increased vascular calcification. Furthermore, reduced bone mineral density is prevalent in older persons with lower body mass index (BMI). Therefore, although BMI and coronary artery calcification (CAC) exhibit a positive relationship in younger persons, it is predicted that in older persons and/or those at risk for osteoporosis, an inverse relationship between BMI and CAC may apply. We sought to explore this hypothesis in a large group of patients with coronary artery disease undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

We accessed our single-center registry for 07/01/1999 to 06/30/2009, extracting data on all patients that underwent PCI. To minimize bias we excluded those at the extremes of age or BMI and non-Black/Hispanic/Caucasians, leaving 9993 study subjects (age 66.6±9.9 years). Index lesion calcification (ILC) was analyzed with respect to BMI. Comparing index lesions with no angiographic calcification to those with the most severe, mean BMI decreased by 1.11 kgm(-2); a reduction of 3.9% (P<0.0001). By multivariable modeling, BMI was an independent inverse predictor of moderate-severe ILC (m-sILC; odds ratio [OR] 0.967, 95% CI 0.953-0.980, P<0.0001). Additional fully adjusted models identified that, compared to those with normal BMI, obese patients had an OR of 0.702 for m-sILC (95% CI 0.596-0.827, P<0.0001).

CONCLUSIONS

In a large group of PCI patients, we identified an inverse correlation between BMI and index lesion calcification. These associations are consistent with established paradigms and suggest a complex interrelationship between BMI, body size and vascular calcification.

[Identification and quantification of fat compartments with CT and MRI and their importance]

In addition to being overweight, as defined by the BMI, the distribution, composition and biological activity of adipose tissue are key elements in the cardiovascular risk stratification of patients. Several non-invasive techniques have been developed to quantify local fat depots, whereby computed tomography (CT) and magnetic resonance imaging (MRI) are the most important. In general adipose tissue is subdivided into subcutaneous and visceral compartments and although both are associated with cardiovascular risk factors and disease, visceral fat has on average a stronger association and a clearly higher biological activity independent of traditional risk factors. This maybe explained by the higher endocrine activity and secretion of pro-inflammatory cytokines by visceral fat. Especially pericardial adipose tissue, a local visceral fat depot surrounding the coronary arteries, is associated with the presence, extent and severity of coronary artery disease. However, several other local fat depots have been identified and associations with various diseases have been established. This article gives an overview over the current methods for the identification and quantification of local fat depots and summarizes the hypothesized and known associations. Furthermore, it gives an overview of the potential significance of individual local fat depots for cardiovascular risk stratification.

Resting heart rate and coronary artery calcium in postmenopausal women

OBJECTIVE

To test the hypothesis of a significant association between resting heart rate (RHR) and coronary artery calcium (CAC).

METHODS

This is a cross-sectional study of a subset of women enrolled in the estrogen-alone clinical trial of the Women's Health Initiative (WHI). We used a longitudinal study that enrolled 998 postmenopausal women with a history of hysterectomy between the ages of 50 and 59 at enrollment at 40 different clinical centers. RHR was measured at enrollment and throughout the study, and CAC was determined approximately 7 years after the baseline clinic visit.

RESULTS

The mean (standard deviation [SD]) age was 55 (2.8) years. With adjustment for age and ethnicity, a 10-unit increment in RHR was significantly associated with CAC (SD 1.18, 95% confidence interval [CI] 1.01-1.38), but this was no longer significant after adjustment for body mass index (BMI), income, education, dyslipidemia, diabetes, smoking, and hypertension (SD 1.06, 95% CI 0.90-1.25). In a fully adjusted multivariable model, however, there was a significant interaction (p=0.03) between baseline RHR and systolic blood pressure (SBP) for the presence of any CAC. Compared to women with an RHR < 80 beats per minute (BPM) and an SBP < 140 mm Hg, those who had an RHR ≥ 80 BPM and an SBP ≥ 140 mm Hg had 2.66-fold higher odds (1.08-6.57) for the presence of any CAC.

CONCLUSIONS

Compared to those with normal BP and RHR, postmenopausal, hysterectomized women with an elevated SBP and RHR have a significantly higher odds for the presence of calcified coronary artery disease.

Omentin inhibits osteoblastic differentiation of calcifying vascular smooth muscle cells through the PI3K/Akt pathway

Arterial calcification is positively associated with visceral adiposity, but the mechanisms remain unclear. Omentin is a novel adipokine that is selectively expressed in visceral adipose tissue. The levels of circulating omentin are decreased in obesity, and they correlate negatively with waist circumference. This study investigated the effects of omentin on the osteoblastic differentiation of calcifying vascular smooth muscle cells (CVSMCs), a subpopulation of aortic smooth muscle cells putatively involved in vascular calcification. Omentin inhibited mRNA expression of alkaline phosphatase (ALP) and osteocalcin; omentin also suppressed ALP activity, osteocalcin protein production, and the matrix mineralization. Furthermore, omentin selectively activated phosphatidylinositol 3-kinase (PI3K) downstream effector Akt. Moreover, inhibition of PI3K or Akt activation reversed the effects of omentin on ALP activity and the matrix mineralization. The present results demonstrate for the first time that omentin can inhibit osteoblastic differentiation of CVSMCs via PI3K/Akt signaling pathway, suggesting that the lower omentin levels in obese (specially visceral obese) subjects contribute to the development of arterial calcification, and omentin plays a protective role against arterial calcification.

A prospective study of abdominal obesity and coronary artery calcium progression in older adults

OBJECTIVE

Little is known about obesity measurements and coronary artery calcium (CAC) progression in older adults. We examined the sex-specific association between measures of body size and fat distribution with CAC progression.

SUBJECTS AND METHODS

Participants were 156 men and 182 women (mean age 67 yr) without known heart disease who had electron-beam computed tomography for CAC at baseline and again 4.5 yr later. Obesity assessments were weight, height, body mass index, waist and hip circumference, waist to hip ratio, waist to height ratio, sc and visceral adipose tissue (SAT, VAT), and SAT to VAT ratio based on abdominal electron-beam computed tomography. CAC progression was defined as categorical (square root increased on total CAC volume score > or = 2.5 mm(3)) and continuous variables.

RESULTS

During the follow-up, 55% of men and 38.5% of women had CAC progression. Increased waist to hip ratio (> or = 0.9 for men, > or = 0.85 for women) and waist to height ratio (> or = 0.55 for men, > or = 0.54 for women) were positively and independently associated with CAC progression [median (interquartile range)] [60.8 (145) vs. 10.8 (56) mm(3), P = 0.002 and 50 (153) vs. 22(84) mm(3), P = 0.03, respectively]. In women but not men, an increased waist circumference (> 88 cm) independently predicted CAC progression (odds ratio 3.0 95% confidence interval 1.03-8.0, P = 0.04), whereas VAT to SAT ratio predicted CAC progression in men but not women (odds ratio 2.8 95% confidence interval 1.01-7.8, P = 0.04).

CONCLUSION

In this study of older adults without known heart disease, abdominal obesity was an independent predictor of CAC progression. These results point to the importance of using clinical measurements of abdominal obesity to identify individuals at increased risk for atherosclerosis.

Comparative relation of general, central, and visceral adiposity measures for coronary artery calcium in subjects without previous coronary events

It is unclear whether visceral obesity is largely responsible for an increased risk of coronary artery disease. In the present study, 1,054 men underwent coronary artery calcium (CAC) scoring and abdominal computed tomography. Risk factor information, body mass index, waist circumference, and waist-to-hip ratio were collected for all participants. The total fat, visceral fat, and subcutaneous fat areas were also quantified at the level of the umbilicus using computed tomography. We then investigated the association of these obesity parameters with the CAC score. Participants with a CAC score >10 had a larger waist circumference (97 +/- 12 vs 95 +/- 12 cm, p <0.001), a larger total fat area (434 cm(2), interquartile range 339 to 565, vs 415 cm(2), interquartile range 315 to 521; p = 0.005), a larger visceral fat area (200 cm(2), interquartile range 143 to 256, vs 175 cm(2), interquartile range 124 to 225; p <0.001), and a greater waist-to-hip ratio (0.93 +/- 0.07 vs 0.91 +/- 0.07, p <0.001) than those with a CAC score of < or =10. Those with a CAC score >10 also tended to have a greater body mass index and larger subcutaneous fat area. After adjusting for traditional cardiovascular risk factors, however, only a large waist circumference (odds ratio 1.5, 95% confidence interval 1.04 to 2.0), a high total fat area (odds ratio 1.5, 95% confidence interval 1.1 to 2.1), and a high waist-to-hip ratio (odds ratio 1.6, 95% confidence interval 1.2 to 2.3) remained significantly associated with a CAC score >10. In conclusion, the measures of central obesity were more strongly associated with the CAC score than either the parameters assessing overall obesity or other more direct measures of visceral adiposity. These findings suggest that the total amount of central obesity is more important than the relative distribution of visceral versus subcutaneous fat.

Relation of subcutaneous and visceral adipose tissue to coronary and abdominal aortic calcium (from the Framingham Heart Study)

Body fat distribution might be differentially associated with subclinical cardiovascular disease. We examined whether the body mass index, waist circumference, and subcutaneous and visceral adipose tissue are associated with the prevalence of either coronary or abdominal aortic calcium in the Framingham Heart Study. Participants (n = 3,130, mean age 52 years, 49% women) free of clinical cardiovascular disease from the Framingham Heart Study underwent multidetector computed tomographic assessment to quantify the subcutaneous and visceral fat volume and coronary and abdominal aortic calcification. Coronary artery calcification and abdominal aortic calcium were examined in relation to the body mass index, waist circumference, subcutaneous adipose tissue, and visceral adipose tissue in age-, gender-, and multivariate-adjusted models. All measures of adiposity were associated with coronary aortic calcium in the age- and gender-adjusted models (all p <0.008). All relations were attenuated in the multivariate models (all p >0.14). The body mass index, waist circumference, and visceral adipose tissue (but not the subcutaneous adipose tissue) were associated with abdominal aortic calcification in the age- and gender-adjusted models (all p <0.012). However, all relations were attenuated in the multivariate models (all p >0.23). Similar findings were observed in the quartile-based analyses. In conclusion, the general measures of obesity and measures of central abdominal fat are related to the coronary aortic calcium and abdominal aortic calcium levels. However, these cross-sectional associations are attenuated by cardiovascular disease risk factors, possibly because they mediate the association between adiposity measures and subclinical cardiovascular disease.

Cardiac remodeling in obesity

The dramatic increase in the prevalence of obesity and its strong association with cardiovascular disease have resulted in unprecedented interest in understanding the effects of obesity on the cardiovascular system. A consistent, but puzzling clinical observation is that obesity confers an increased susceptibility to the development of cardiac disease, while at the same time affording protection against subsequent mortality (termed the obesity paradox). In this review we focus on evidence available from human and animal model studies and summarize the ways in which obesity can influence structure and function of the heart. We also review current hypotheses regarding mechanisms linking obesity and various aspects of cardiac remodeling. There is currently great interest in the role of adipokines, factors secreted from adipose tissue, and their role in the numerous cardiovascular complications of obesity. Here we focus on the role of leptin and the emerging promise of adiponectin as a cardioprotective agent. The challenge of understanding the association between obesity and heart failure is complicated by the multifaceted interplay between various hemodynamic, metabolic, and other physiological factors that ultimately impact the myocardium. Furthermore, the end result of obesity-associated changes in the myocardial structure and function may vary at distinct stages in the progression of remodeling, may depend on the individual pathophysiology of heart failure, and may even remain undetected for decades before clinical manifestation. Here we summarize our current knowledge of this complex yet intriguing topic.

The impact of the menopause on coronary artery calcification examined by multislice computed tomography scanning

BACKGROUND AND AIMS

To examine whether there is a difference in coronary artery calcification (CAC) scores between males and females aged above 50 years.

METHODS AND RESULTS

A total of 479 subjects aged between 40 and 70 years with no clinical or family history of cardiovascular disease (CVD) were enrolled for this study. All subjects were assessed by multislice CT scanning (MCTS), and the CAC scores obtained were assigned to one of four quartiles for further assessment and comparison. The main outcome evaluated was the percentage of high CAC scores and mean CAC scores, comparing males and females of different age groups. This study found that the percentage of high CAC scores increased markedly from 5% (40-49 age group) to 21.2% (50-59 age group) among females. The increase was significantly less when comparing males from different age groups (from 25% in the 40-49 age group to 31.2% in the 50-59 age group). Females had higher odds ratios (ORs) postmenopausally (4.3 in the 50-59 age group) than males in the same age group (1.6).

CONCLUSIONS

These initial findings seem to indicate that above 50 years of age, CAC is more dependent on age in females than in males, which might be due to the effect of the menopause.

Renal artery calcium is independently associated with hypertension

OBJECTIVES

We tested the hypothesis that renal artery calcium (RAC), a marker of atherosclerotic plaque burden, is also significantly associated with higher blood pressure levels and a diagnosis of hypertension.

BACKGROUND

In the nonrenal systemic vasculature, atherosclerotic plaque burden has been shown to be significantly associated with hypertension.

METHODS

A total of 1,435 consecutive patients were evaluated at a university-affiliated disease prevention center for the extent of calcified atherosclerosis in the systemic vasculature.

RESULTS

The overall prevalence of calcium in either renal artery was 17.1%, with men having a significantly higher prevalence (19.0%, 153 of 804) than women (14.7%, 93 of 631) (p = 0.03). After adjustment for age and gender, subjects with a RAC score >0 had a significantly higher prevalence of hypertension (41.2 vs. 29.5, p < 0.01). In a logistic model that adjusted for age, gender, body mass index, percent body fat, diabetes, smoking, dyslipidemia, and the extent of calcified atherosclerosis in the nonrenal vasculature, those with any RAC had a significantly higher odds ratio (1.61, p = 0.01) for hypertension than those with no RAC.

CONCLUSIONS

The results of this study suggest that the presence of RAC is associated with higher odds for prevalent hypertension, independent of CVD risk factors and the extent of calcified atherosclerosis in the nonrenal vasculature.

Impact of obesity on coronary artery calcification examined by electron beam computed tomographic scan

AIM

Obesity is highly associated with cardiovascular disease (CVD). The early and non-invasive diagnosis method for asymptomatic obese is desirable. The aim of this study was to examine the impact of obesity on coronary artery calcification (CAC) by electron beam computed tomographic (EBCT) scan.

METHODS

A total of 465 subjects (i) aged between 40 and 65 years, (ii) being Chinese, (iii) without clinical or historical angiographic obstruction or arrhythmia and (iv) without family history of CVD were enrolled in this study. All the subjects were assigned to one of the EBCT CAC score categories according to the quartiles: quartile 1 (<25%), quartile 2 (25-49%), quartile 3 (50-75%) and quartile 4 (>75%), for further assessment and comparison. The main outcome evaluated is the difference in CAC scores between obese [body mass index (BMI): > or =30 kg/m(2)] and healthy (BMI: 18.5-25.0 g/m(2)) BMI groups. The trends of the characteristics in CAC quartile groups and the odds ratios (ORs) were also evaluated.

RESULTS

The mean of CAC scores between the obese and the healthy BMI groups showed significant difference (p = 0.05). The obese subjects had higher ORs (1.0-5.8 times) than those with BMI < 23 kg/m(2), and male had higher ORs (1.1-3.6 times) than female, to develop the high CAC score quartile group.

CONCLUSION

This study demonstrated that the obese BMI group has a higher mean of CAC scores than the healthy BMI group of middle-aged, asymptomatic, Chinese adults. The obese males have higher risk of developing high CAC scores, which might induce CVD.

AHSG gene variant is associated with leanness among Swedish men

Alpha(2) Heremans-Schmid glycoprotein (AHSG) is a plasma protein inhibiting the activity of the insulin receptor tyrosine kinase. Ahsg knock-out mice have increased insulin sensitivity and are resistant to diet-induced obesity. We hypothesized that functional variants of the AHSG gene segregating in the human population would reflect variation in body mass index (BMI). We genotyped 356 overweight or obese (BMI: 37.2 [25.0-66.5] kg/m(2)) and 148 lean (BMI: 23.7 [23.4-24.9] kg/m(2)) otherwise healthy Swedish men for three non-synonymous single-nucleotide polymorphisms (SNPs) within exon 6 (rs4917) and exon 7 (rs4918 and Arg299Cys) and one SNP in intron 1 (rs2593813) of the AHSG gene. The G/G genotype for rs2593813 was more common among lean than among obese and overweight individuals (odds ratio = 2.01, P = 0.009), whereas rs2593813 was in strong linkage disequilibrium (|D'| > or = 0.97) with rs4917 and rs4918. Homozygosity for the rs2593813:G-rs4917:Met-rs4918:Ser haplotype conferred an increased risk for leanness (odds ratio=1.90, P = 0.027). rs4917:Met and rs4918:Ser have previously been associated with lower AHSG protein level. A common variant of AHSG, previously associated with a lower AHSG protein level, is thus more common among lean than obese and overweight men, supporting the results from Ahsg knock-out mice, namely, that AHSG modulates body mass.