Table 2. Univariate Correlations Between Adiponectin Levels and Other Metabolic Syndrome-Related Traits for All 424 Participants

IbIc and BMI for BMI (ug/ml) in ad 33z2I7-anil20   67S F685 §5-95 96-105Age range (Years)       BFemale OMale 1. pO. 12r=0.43. p=0.005* #§<65 66-28 6-85 86-95 96-108Age range (Years)Biomale OMale yg 3150.26, p=0.027 ay         <65 66-75 16-85Age Range (Years)

Trait Adiponectin p Value Age* 0.22 ,.0001 BMI* (cid:2)0.21 ,.0001 % of Fat* (cid:2)0.16 .0002 Triglyceridey (cid:2)0.19 .0005 HDLy 0.23 ,.0001 LDLy 0.02 .79 Systolicy 0.09 .0878 Diastolicy 0.10 .0497 Waist circumferencey (cid:2)0.11 .0292 Glucosey (cid:2)0.09 .0917 LDL particle sizey 0.27 ,.0001 HDL particle sizey 0.24 ,.0001

Notes: *Adjusted for age and sex (except age). yAdjusted for age, sex, and BMI. BMI ¼ body mass index; HDL ¼ high-density lipoprotein; LDL ¼ low- density lipoprotein.

levels between offspring and control was 2.68 lg/mL, p ¼ .009. HDL level remained an independent significant deter- minant of adiponectin (p ¼ .02). There was no significant interaction between sex and offspring status. However, the difference between controls and offspring among men was significant (mean difference ¼ 3.21 lg/mL; p ¼ .022) and was greater than in women, where the difference was not significant (mean difference ¼ 1.74 lg/mL; p ¼ .18) fol- lowing adjustment for age and BMI. Higher adjusted adiponectin levels in offspring of long-lived probands than in controls, particularly among men, is consistent with our hypothesis that high adiponectin levels pose a survival advantage.

One possible explanation for increased adiponectin levels in offspring of long-lived probands is that some of these individuals may have inherited a genotype that leads to a favorable (increased) adiponectin level phenotype. To examine this possibility further, we genotyped common ADIPOQ variants, including some that were previously shown to influence adiponectin levels (28), and performed association analysis between adiponectin levels and these variants. When these SNPs were included separately as additional covariates in the regression models (Table 3), two SNPs were significantly associated with increased adipo- nectin levels: rs17300539 (p ¼ .02) and SNP þ2019 (p ¼ .02). Linkage disequilibrium between the two SNPs as estimated by r2 was low (r2 ¼ 0.05), suggesting two independent effects. The mean adiponectin difference associated with rs17300539 in a dominant model was significant and slightly higher in men (mean difference ¼ 2.22 6 1.11 lg/mL; p ¼ .047) than in women (mean difference ¼ 1.77 6 1.21 lg/mL; p ¼ .15). Similarly, in an additive model the effect of SNPþ2019 was significant and slightly higher in men (mean difference ¼ 1.45 6 0.71 lg/ mL; p ¼ .043) than in women (mean difference ¼ 1.18 6 0.82 lg/mL; p ¼ .15). No significant associations of adiponectin levels with adiponectin genotypes were seen within the proband group (data not shown).

Figure 1. Adiponectin levels according to age. a, Adiponectin levels, adjusted for sex and body mass index (BMI) in long-lived probands and controls. This group represents a continuous age group of unrelated individuals from 51 to 106 years of age. b, Adiponectin levels, adjusted for BMI in long-lived probands and controls stratified by sex. c, Adiponectin levels, adjusted for BMI in offspring of long-lived probands stratified by sex. *p ¼ .05, **p ¼ .01 for comparison to the ,65-year-old group. #p , .05 for comparison to the 66- to 75-year-old group. zp , .05 for comparison to the 76- to 85-year-old group. §p , .01 for comparison to females within stratified group.

control–offspring differences in adiponectin levels separately in individuals younger than 85 years versus 85 years old or older. Results were similar in the younger than 85 years group (mean difference ¼ 2.31 6 0.97 lg/mL, p ¼ .02). In the 85 years old or older group, which only contained 30 individuals, the difference was greater (3.47 6 3.85 lg/mL) but not significant (p ¼ .38). We also undertook a further analysis which, in addition to adjusting for age, sex, and BMI, included ln-triglycerides and HDL and LDL levels as covariates. In this analysis, the difference in adiponectin

We also compared the frequency of the adiponectin SNP genotypes among probands, offspring, and controls in the

Table 3. Association of ADIPOQ SNP Genotypes With Adiponectin Levels (Provided as Least Squared Means þ SE) in Offspring and Controls Combined Adjusted for Age, Sex, BMI, and Offspring Status

p Value Frequency Additive Dominant SNP Allele 1 Allele 2 11 (No. of Participants) 12 (No. of Participants) 22 (No. of Participants) of Allele 2 (Bonferroni) rs17300539 G A 11.82 6 0.45 (195) 14.13 6 0.76 (69) 11.73 6 2.86 (5) 0.15 .02 (.14) .01 (.07) rs266729 C G 12.39 6 0.53 (148) 12.24 6 0.64 (102) 14.03 6 1.73 (14) 0.25 .67 .94 rs182052 G A 12.92 6 0.61 (110) 11.82 6 0.60 (117) 14.97 6 1.47 (19) 0.32 .22 .43 rs822396 A G 12.49 6 0.45 (205) 11.81 6 0.87 (55) 19.42 6 6.41 (1) 0.11 .70 .57 rs2241766 T G 12.75 6 0.51 (158) 11.78 6 0.80 (65) 11.54 6 1.95 (11) 0.18 .27 .26 rs17366743 T C 12.22 6 0.39 (258) 15.63 6 1.69 (14) 7.14 6 6.30 (1) 0.03 .18 .09 APM1þ2019 A deletion 11.22 6 0.75 (74) 12.90 6 0.51 (156) 13.41 6 0.74 (76) 0.50 .02 (.14) .03 (.21)

Note: SNP ¼ single nucleotide polymorphism; SE ¼ standard error; BMI ¼ body mass index.