In the GHS-prospective designs blood samples were collected between 8:00 and 9:00 AM after an overnight fast.
In the NHS and HPFS, blood samples were collected in EDTA blood tubes in the men and heparin blood tubes in the women, chilled, and sent back by prepaid overnight courier. Once in the laboratory, the samples were centrifuged and aliquoted into cryotubes as plasma, buffy coat, and red blood cells. Cryotubes were then stored in liquid nitrogen freezers at −130°C or lower [40 (link)].
In the GHS-prospective design, serum total and HMW adiponectin concentrations were measured by ELISA (Alpco, Salem, NH) as previously described [41 (link)]. The intra-assay coefficients of variation were 5.4 and 4.9, and 5.0 and 4.8% for total adiponectin and HMW adiponectin, respectively.
In the NHS and HPFS, plasma total adiponectin was measured separately, in two different laboratories, by competitive radioimmunoassay (Linco Research, St. Charles, MO). A similar coefficient of variation ranging 3-4%, was observed in both cohorts [42 (link)].
In the NHS and HPFS, blood samples were collected in EDTA blood tubes in the men and heparin blood tubes in the women, chilled, and sent back by prepaid overnight courier. Once in the laboratory, the samples were centrifuged and aliquoted into cryotubes as plasma, buffy coat, and red blood cells. Cryotubes were then stored in liquid nitrogen freezers at −130°C or lower [40 (link)].
In the GHS-prospective design, serum total and HMW adiponectin concentrations were measured by ELISA (Alpco, Salem, NH) as previously described [41 (link)]. The intra-assay coefficients of variation were 5.4 and 4.9, and 5.0 and 4.8% for total adiponectin and HMW adiponectin, respectively.
In the NHS and HPFS, plasma total adiponectin was measured separately, in two different laboratories, by competitive radioimmunoassay (Linco Research, St. Charles, MO). A similar coefficient of variation ranging 3-4%, was observed in both cohorts [42 (link)].