Article Figures & Data
Figures
- Figure 1.
Plasma lipoproteins comparing hepatic synthesis and lipid trajectory of TG-rich particles: A) With and B) without insulin resistance.
HbA1c—hemoglobin A1c, HDL—high-density lipoprotein cholesterol, IDL—intermediate-density lipoprotein cholesterol, LDL—low-density lipoprotein cholesterol, TG—triglyceride, VLDL—very low-density lipoprotein cholesterol.
- Figure 2.
Comparison of mortality rates in non-smokers by BMI or WHtR deciles over 20 years
BMI—body mass index, WHtR—waist-to-height ratio.
Data from Ashwell et al.40
- Figure 3.
Adjusted mortality HRs (with 95% CIs represented by error bars) for waist circumference comparing highest and lowest values by category of BMI
BMI—body mass index, HR—hazard ratio. Data from Cerhan et al.53
Tables
- Table 1.
Anthropometric measures of body fat distribution: A) Mass-based and B) distribution-based measures.
A) MASS-BASED MEASURE DEFINITION COMMENTS Body mass index11 Weight in kg divided by the square of the height in m Does not distinguish between lean and fat tissue mass • Underweight < 18.5 kg/m2 Associated with higher mortality • Normal weight
• Overweight18.5–24.9 kg/m2
25.0–29.9 kg/m2Lowest mortality associated with these categories • Obesity class 1 30.0–34.9 kg/m2 No consistent association with increased mortality • Obesity class 2
• Obesity class 335.0–39.9 kg/m2
≥ 40.0 kg/m2Direct association with increased mortality B) DISTRIBUTION-BASED MEASURES VALUES REPRESENTING INCREASED RISK SURROGATE MEASURES OF CENTRAL OR VISCERAL ADIPOSITY Waist circumference Females ≥ 80 cm
Males ≥ 95 cmCut points vary according to ethnicity, sex, and age12 Waist-to-hip ratio Females ≥ 0.85
Males ≥ 0.95Cut points not well established for ethnicity13 Waist-to-height ratio Increased risk 0.50–0.60
Substantial risk > 0.60Cut points the same for ethnicity, sex, and age12
Best predicts visceral fat mass14,15 VARIABLES CHARACTERISTICS SUBCUTANEOUS FAT VISCERAL FAT Clinical measurement Body mass index Waist circumference, waist-to-height ratio, waist-to-hip ratio Association with cardiometabolic disease16 Association with mortality is inconsistent Direct linear association with mortality Function15,18 Metabolic sink and longer-term energy storage Short-term energy source Cardiac risk23 Moderate High Metabolic risk24 Moderate High Inflammation22 Moderate High Catecholamine response22 Moderate Rapid Insulin sensitivity17 Moderate Low Metabolic flux18 Low High Trend with age25 Increased to age 65 y, then reduced Gradual increase Storage duration26 Long Short Effect of exercise27 High levels needed for weight change Low levels effective for cardiometabolic benefit Adverse effects of refined carbohydrate28 Moderate High - Table 3.
Prospective observational studies and related SRs and MAs of studies relating normal-weight central obesity to mortality
STUDY AND YEAR STUDY TYPE (DURATION) STUDY OBJECTIVES NO. AND AGE OF PARTICIPANTS RESULTS COMMENTS Coutinho et al, 201343 SR of prospective observational studies and collaborative analysis (0.5–7.4 y) Relation of measures of central obesity to mortality 15 923 patients with known CAD Mean (SD) age 65.7 (11.5) y Highest mortality category combined lowest BMI with highest WHR or WC; HR = 1.7 Central obesity associated with equal increase in mortality risk in lean and obese patients. Increased BMI was associated with reduced risk in these patients Kramer et al, 201344 MA of prospective observational studies (3–30 y) Relation of cardiometabolic risk and BMI category to CVD events and all- cause mortality 61 386 adults from the general population
Mean age range 44–60 yHighest mortality or CVD event rate was similar in metabolically unhealthy normal-weight and obese participants; HR = 2.65 compared with those of normal weight and metabolic health Did not specifically consider central obesity. Metabolic health was based on absence of metabolic syndrome components, insulin resistance, or inflammatory markers Carmienke et al, 201339 SR and regression MA of prospective cohorts (5–24 y) Relation of measures of abdominal obesity parameters to mortality 689 465 healthy adults
Age ≥ 18 yHighest mortality category combined lowest BMI with highest WHR or WC WHR, WC, or WHtR combined with BMI gives best mortality prediction. In participants > 65 y there was a non-significant or negative association with increasing BMI, WC, and WHR Folsom et al, 200045 Prospective observational study (11–12 y) Relation of BMI, WC, and WHR to mortality, cancer, diabetes, hypertension, and fracture 31 702 healthy US women
Age 55–69 yHighest mortality category combined lowest BMI with highest WHR WHR had the best mortality prediction Pischon et al, 200846 Prospective observational study (9.7 y) Association of distribution of adiposity with risk of death 359 387 participants from general European population
Age 25–70 yHighest mortality associated with lowest BMI percentile having highest WC or WHR Association of BMI with mortality is J shaped.
Measures of central obesity showed positive linear association with mortality when adjusted for BMIZhang et al, 200847 Prospective observational study (16 y) Relation of abdominal adiposity to premature death 44 636 US women from the Nurses’ Health Study
Age 30–55 yHighest mortality category combined highest BMI and highest WC or WHR. Risk was only slightly lower for normal BMI with high central obesity WC and WHR were both directly associated with mortality Koster et al, 200848 Prospective observational study (9 y) Relation of WC to all-cause mortality 245 533 US adults
Age 51–72 yNormal weight with high WC increased mortality by 22%.
Exceeded only by class 2 and 3 obesity with high WCWC used as measure of central obesity in mortality prediction Reis et al, 200949 Prospective observational study (12 y) Relation of BMI, WHR, and WTR to mortality 13 065 participants from the general US population
Age 30–102 yHighest mortality category combined lowest BMI with highest WHR or WTR WHR or WTR had the best mortality prediction. No association at > 65 y of age Romero-Corral et al, 200950 Prospective observational study (8.8 y) Relation of body fat percentage to cardiovascular mortality and metabolic dysregulation in participants with normal BMI 6171 US patients with normal BMI and CAD
Age ≥ 20 yHigh body fat percentage and WC were associated with increased risk of metabolic syndrome. CVD mortality increased in normal-weight obese women (HR = 2.20) compared with nonobese women Body fat measured by bioimpedance. Body fat percentage did not correlate with all-cause mortality in women or men at any BMI Staiano et al, 201251 Prospective observational study (13 y) Relation of BMI, WC, and WHR to CVD and all-cause mortality 8061 Canadian adults
Age 18–74 yNo mortality increase with WC in normal-weight adults. Highest mortality in highest WC terciles of obese adults WC had the best association with CVD and all-cause mortality Thomas et al, 201352 Prospective observational study (mean [SD] 5.6 [2.4] y) Relation of obesity measured by BMI or WC on mortality at differing ages 119 010 French participants with BMI > 20 kg/m2
Age 17–85 yMortality at BMI 20–25 kg/m2 and WC ≥ 102 cm ... increased 2-fold at age < 55 y and
increased 5-fold at age 55–65 y
No association at age > 65 yMortality risk higher for central obesity in normal BMI range than in class 2 and 3 obesity. WC gives best mortality prediction at < 65 y of age. Neither WC nor BMI are useful in the elderly Cerhan et al, 201453 Pooled data from 11 prospective observational studies (median 9 y, maximum 21 y) Relation of WC to mortality across entire range of BMI categories 650 386 non-Hispanic white adults
Age 20–83 yHighest mortality associated with BMI ranges < 20 and ≥ 35 kg/m2 in those with highest WC. Highest WC in those with BMI 20–22.5 kg/m2 had higher mortality than those with class 1 obesity at highest WC WC should be assessed in combination with BMI even in those in normal BMI range. WC is directly associated with mortality at all levels of BMI Sahakyan et al, 201554 Prospective observational study (14.3 y) Relation of central obesity and survival in adults of normal body weight 16 124 US adults with BMI ≥ 18.5 kg/m2
Age 18–90 yMen with normal-weight central obesity had higher mortality risk than any other BMI and WHR combination.
Similar women had 40% and 32% relative risk increase compared with overweight and obese women without central obesityWHR used as measure of central obesity in mortality prediction Klingberg et al, 201555 Prospective observational study (average 6 y) Relation of baseline WC and change in WC to morality and CVD 2492 healthy Danish and Swedish women
Age 44–74 y at baselineAssociation of mortality with both high baseline WC and large increase in WC over time; particularly high in those with BMI < 25 kg/m2 WC used in mortality prediction. Hip circumference was unrelated to mortality Sharma et al, 201656 Prospective observational study (average 7.1 y) Relation of WC or WHR and BMI to mortality in elderly patients with CVD 7057 elderly patients with CAD
Mean age 73 yHighest mortality in patients with normal BMI and central obesity Highlights importance of including WC or WHR along with BMI when making adiposity-related mortality assessment Hamer et al, 201757 Prospective observational study (average 9 y) Determine whether WHR is more predictive of mortality than BMI is 42 702 UK adults
Mean age 57.7 yNormal weight with central obesity showed highest mortality; HR = 1.22 for death WHR used as measure of central obesity in mortality prediction BMI—body mass index, CAD—coronary artery disease, CVD—cardiovascular disease, HR—hazard ratio, MA—meta-analysis, SR—systematic review, UK—United Kingdom, US—United States, WC—waist circumference, WHR—waist-to-hip ratio, WHtR—waist-to-height ratio, WTR—waist-to-thigh ratio.
In this issue
Normal-weight central obesity
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