Table 1.
Studies examining human milk leptin.
| Author | Year | Sample Size (n) | Sample Type | Sampling | Time of the Day (h) | Time Postpartum |
Preparation | Method | Intra, Inter Assay (%CV) |
LOD (ng/mL) |
R (%) | Concentration (ng/mL) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Houseknecht et al. [20] | 1997 | 14 | - | 12 h fast | 08:00 | - | SM and Wm | RIA | 3.0, 12.6 | 0.3 | SM: 90 WM: 82 |
WM, 10.1 ± 2.6; SM, 1.5 ± 0.87 |
| Uçar et al. [21] | 2000 | 18 | C, M | pre- and post-feed | 9:00–12:00 | 3–120 d | SM | RIA | - | 0.5 | - | (0.8–15) (range) |
| Lönnerdal and Havel [22] | 2000 | - | M | - | - | 2–4 mo | SM and WM | RIA | - | - | - | WM, 32.7 ± 14.1 SM, 0.2 ± 0.1 |
| Resto et al. [23] | 2001 | 29 | M | - | - | 1–4 wk | M, added pancreatic lipase, NaHCO3 |
RIA | - | - | - | 5.28 (24.79) |
| Uysal et al. [24] | 2002 | 50 | M | 2 h after last feed | 8:00–10:00 | 1,2, 3 mo | SM | RIA | <6, - | 0.1 | - | Non-Ob, 0.37 ± 0.4 Ob, 0.27 ± 0.2 |
| Bielicki et al. [25] | 2004 | 33 | C, M | 1–3 h after breakfast | - | 2–3, 4–5 d 4–6 wk |
WM | RIA | <10, 9.7 | 0.25 | 97 | Preterm, 0.63 ± 0.18 Term, 1.34 ± 0.14 |
| Dundar et al. [26] | 2005 | 47 | M | pre-feed | 10:00–11:00 | 15 d, 1, 2, 3 mo | WM | RIA | 6.2, - | 0.5 | 83 ± 4 | 15 d, AGA, 18.4 ± 2; LGA, 28.5 ± 4.4; SGA, 13.4 ± 2.2 |
| Ilcol et al. [27] | 2006 | 160 | C, M | pre-feed, 3 h after breakfast | morning | 2, 8, 25 d | WM | IRMA | <5, 7 | 0.1 | - | 2 d, 3.35 ± 0.25; 8 d, 2.65 ± 0.21; 25 d, 1.63 ± 0.18 |
| Bronsky et al. [28] | 2006 | 59 | C | collected on EDTA and aprotinin | after 7:00 | 1–2 d | SM | ELISA | 7.6, 9.1 | 0.05 | - | 0.50 (0.05) mean (SEM) |
| Miralles et al. [29] | 2006 | 28 | M | post-feed | morning | 1, 3, 6, 9 mo | WM | ELISA | - | 0.008 | 103.1 ± 1.4 | 1 mo, 0.156 ± 0.039 |
| Weyermann et al. [17] | 2006 | 766 | M | pre-feed | - | 6 wk, 6 mo |
SM | ELISA | <7 | - | - | 12.8 ± 10.1 |
| Weyermann et al. [30] | 2007 | 767 | M | - | - | 6 wk | SM | ELISA | <7, - | - | - | 0.175 (0–4.1) median (range) |
| Aydin et al. [31] | 2008 | 31 | C, M | pre-feed, collected on aprotinin | 9:00 | 2, 25 d | SM | ELISA | - | - | - | C, 2.01 ± 0.34; M, 2.04 ± 0.67 |
| Savino et al. [32] | 2010 | 36 | - | - | - | <6 mo | SM | RIA | <5, 8 | 0.04 | - | 0.51 (0.34) |
| Bronsky et al. [33] | 2011 | 72 | C, M | collected on EDTA + protease inhibitor | - | 1 d; 1, 3, 6, 12 mo | SM | ELISA | 6, 9 | 0.5 | - | 1 d, 0.3 ± 0.04; 1 mo, 0.2 ± 0.03; 3 mo, 0.1 ± 0.01; 6 mo, 0.1 ± 0.02; 12 mo, 0.2 ± 0.04 |
| Schuster et al. [34] | 2011 | 23 | C, M | - | - | 1, 2, 3, 4 wk 2, 3, 4, 5, 6 mo |
SM | RIA | - | 0.01 | 70.2 ± 8.7 | 1 wk, 0.21 ± 0.19 6 mo, 0.18 ± 0.15 |
| Eilers et al. [35] | 2011 | 77 | C, M | fasting 2 h prior sampling | 16:00–20:00 | 3 d, 28 d | SM | RIA | 5, 6 | - | ~94 | Preterm, 3 d, 0.7 ± 0.79; 28 d, 0.5 ± 0.4; Term, 3 d, 0.65 ± 0.67; 28 d, 0.5 ± 0.4 |
| Fields and Demerath [36] | 2012 | 19 | M | complete breast expression |
8:00–10:00 | ~1 mo | SM | - | - | - | - | 0.95 ± 0.73 |
| Savino et al. [37] | 2012 | 23 | - | - | - | <6 mo | SM | ELISA | <5, 6.8 | 6 | - | 2.34 (5.73) |
| Schueler et al. [38] | 2013 | 13 | M | overnight fast, pre- and post-feed |
7:00–10:00 | 29–38 d. | SM | RIA | 9.4, - | - | - | pre, 0.9 ± 0.7 post, 1.0 ± 0.8 |
| Chang et al. [39] | 2013 | - | - | - | - | 3–4 mo | SM | ELISA | <5, 6 | 0.5 | - | - |
| Ojeda et al. [40] | 2013 | - | - | - | - | 2 mo | - | ECIs, & ELISA | + | ECIs, 2.6 ± 0.1 ELISA, 2.9 ± 0.5 |
||
| Kon et al. [41] | 2014 | 103 | M | - | Morning | 1, 2, 3 mo | SM | ELISA | 3.7, - | 0.42 | - | LWG, 1 mo, 1.63 (0.27); 3 mo, 1.35 (0.31); NWG, 1 mo, 1.55 (0.17); 2 mo, 1.83 (0.23); 3 mo, 3.29 (0.70) HWG,1 mo: 1.53 (0.29); 2 mo, 2.20 (0.28); 3 mo, 3.57 (1.37) mean (SEM) |
| Brunner et al. [42] | 2014 | 6 wk, 152 6 mo, 120 |
M | overnight fast | Morning | 6 wk, 6 mo |
SM | RIA | - | - | - | 6 wk, 0.11 (0.19); 6 mo, 0.09 (0.18) |
| Khodabakhshi et al. [43] | 2015 | Ob, 40 NW, 40 |
M | overnight fast, 2 h after last breast feed | 8:00–10:00 | 2–5 mo | SM | ELISA | - | - | - | NW, 1.81 (1.65–1.94) Ob, 1.78 (1.67–1.94) |
| Cannon et al. [44] | 2015 | 19 | M | pre- and post-feed | 24 h milk collection | 3–21 wk | SM | RIA | -, 9.9 | 0.017 | 98.4 ± 6.8 | pre, 0.43 ± 0.10, post, 0.42 ± 0.11 |
| Quinn et al. [45] | 2015 | 113 | mid-feed sampling | 6:00–10:00 | 10 d–36 mo | SM | ELISA | - | - | - | 0.3 ± 0.29 | |
| Andreas et al. [46] | 2016 | 120 | - | 1 h fast prior sampling, pre- and post-feed, on protease inhibitors | 10:00–13:00 | 1 wk, 3 mo |
SM | Multiplex assay |
3, - | 3.1 | - | 1 wk, pre 541.7 (161.2); post 614.4 (172.1) 3 mo, pre 684.8 (117.4); post 464.3 (125.1) mean (SEM) |
| Gridneva et al. [47] | 2016 | 27 | M | pre- and post-feed | 09:30–11:30 | 2–5 mo | SM and WM | ELISA | -, <7.2 | - | 97.7 ± 9.7 | WM, 0.51 ± 0.18 [0.23–1.10] SM, 0.28 ± 0.12 [0.20–0.84] |
| Kugananthan et al. [48] | 2016 | 61 | M | pre- and post-feed | 11:00 | 2, 5, 9, 12 mo | SM and WM | ELISA | <5, 7.2 | - | 97.7 ± 9.7 | WM, 2 mo, 0.50 ± 0.16; 5 mo, 0.48 ± 0.16; 9 mo, 0.56 ± 0.11; 12 mo, 0.54 ± 0.14 SM, 2 mo, 0.32 ± 0.16; 5 mo, 0.26 ± 0.07; 9 mo, 0.22 ± 0.03; 12 mo, 0.21 ± 0.02 |
| De Luca et al. [49] | 2016 | 100 | M | over-feed | 9:00–11:00 | 1 mo | SM | RIA | <10, - | 0.5 | + | Non-Ob, 2.5 [2.1–3.0] Ob, 4.8 [4.1–5.6] mean (95% CI) |
| Savino et al. [50] | 2016 | 58 | - | collected on protease inhibitor |
7:00–9:00 | - | SM | RIA | - | 0.04 | - | 0.89 (1.32) |
| Fields et al. [51] | 2017 | 37 | M | complete breast expression |
8:00–10:00 | 1, 6 mo | SM | - | - | - | - | 1 mo (n = 37), 0.589 (0.353–1.45) 6 mo (n = 30), 0.426 (0.145–940) |
| Meyer et al. [52] | 2017 | 147 | M | overnight fast | - | 6 wk, 4 mo | - | RIA | - | - | - | - |
| Quinn and Childs [53] | 2017 | 116 | - | mid-feed | 6:00–10:00 | - | SM | ELISA | 17.8, - | - | - | 0.27 ± 0.25 |
| Nunes et al. [54] | 2017 | 69 | C, M | - | - | 1, 2, 30 d | SM | ELISA | - | - | - | SGA, M, 0.377 (0.36–0.41) GDM, M, 0.460 (0.45–0.70) CTL, M, 0.715 (0.48–0.9) |
| Cannon et al. [55] | 2017 | 20 | - | pre- and post-feed | 24 h milk collection | 6–32 wk | SM | ELISA | -, 9.9 | 0.017 | 98.4 ± 6.8 | 0.51 ± 0.16 (0.42–1.15) |
| Kugananthan et al. [18] | 2017 | 59 | M | pre- and post-feed | 9:30–11:30 | 2, 5, 9, 12 mo | SM and WM | ELISA | -, <7.2 | 0.05 | SM, 96.3 ± 1.2 WM, 97.1 ± 9.1 |
WM, 0.53 ± 0.19 (0.20–2.24) 2 mo, 0.55 ± 0.29; 5 mo, 050 ± 0.17; 9 mo, 0.53 ± 0.15; 12 mo, 0.54 ± 0.13 SM, 0.28 ± 0.12 (0.19–1.46) 2 mo, 0.34 ± 0.21; 5 mo, 0.27 ± 0.07; 9 mo, 0.26 ± 0.09; 12 mo, 0.26 ± 0.08 |
| Gridneva et al. [7] | 2018 | 20 | M | pre- and post-fed | 24 h milk collection | 2, 5, 9, 12 mo | SM and WM | ELISA | -, <7.2 | 0.05 | 97.1 ± 9.1 | WM, 2 mo, 0.50 ± 0.18; 5 mo, 0.49 ± 0.17; 9 mo, 0.56 ± 0.11; 12 mo, 0.50 ± 0.11 SM, 2 mo, 0.34 ± 0.20; 5 mo, 0.26 ± 0.08; 9 mo, 0.21 ± 0.02; 12 mo, 0.21 ± 0.03 |
| Chan et al. [56] | 2018 | 430 | M | pooled 24 h milk collection |
24 h milk collection | 4 mo | SM | ELISA | - | 0.137 | _ | 349 (186–689) |
| Yu et al. [57] | 2018 | 96 | C, M | pre- and post-feed for mature milk | 3 d, 8:00–9:00 42, 90 d, 14:00–16:00 |
3, 42, 90 d |
SM | ELISA | <7.4, 9.3 | - | - | GDM (n = 48), 3 d, 1.28 (0.87–2.63); Healthy (n = 48), 3 d, 1.49 (0.56–3.25) |
| Sadr Dadres et al. [58] | 2019 | 135 | M | 2 h after feeding | 10:00–12:00 | 1, 3 mo | SM | ELISA | <6, 6 | 0.008 | 90–94 | 1 mo, 0.640 ± 0.606 3 mo, 0.484 ± 0.672 |
| Zamanillo et al. [59] | 2019 | 59 | M | - | 9:00–14:00 | 30, 60, 90 d | WM | ELISA | - | - | - | 1 mo, 0.376 ± 0.353; 2 mo, 0.341 ± 0.314; 3 mo, 0.346 ± 0.333 |
| Logan et al. [60] | 2019 | SPATZ, 1090 UBCS, 1006 |
M | 1 h after last feed | 9:00–12:00 | 6 wk, 6 mo |
SM | ELISA | <7.0, - | - | - | SPATZ, 6 wk, 266.5 (152.0–498.0); UBCS, 6 wk, 175.0 (79.8–350.0) |
| Larrosa Haro et al. [61] | 2019 | 131 | M | pre- and post-feed | - | 8, 16 wk | SM | ELISA | - | 0.01 | - | 8 wk, pre, 0.316 (0.50); post, 0.317 (0.57); 16 wk, pre, 0.447 (0.48); post, 0.411 (0.64) |
| Logan et al. [62] | 2019 | 694 | M | 1 h after last feed | 9:00–12:00 | 6 wk, 6 mo, 12 mo |
SM | ELISA | -, 5.8 | - | - | 6 wk (n = 668), 388.8 ± 398.1; 6 mo (n = 445), 269.6 ± 305.3; 12 mo (n = 69), 320.4 ± 345.2 |
| Kocaadam et al. [63] | 2019 | 65 | M | pre-feed, ~2 h fast prior, ~2 h after last feed, on EDTA and aprotinin | 8:00–11:00 | 15–30 d | SM | ELISA | - | - | - | preterm, (n = 31), 2.0 (2.5) term, (n = 34), 0.0 (2.3) |
| Schneider-Worthington et al. [64] | 2020 | 25 | M | - | - | 1 mo | SM | ELISA | 4.48, 13.56 | - | - | 0.47 (0.94) |
| Dal Bello et al. [65] | 2020 | - | - | - | - | - | - | nano-HPLC-HRMS | - | 27 | - | 6.70 |
| Galante et al. [66] | 2020 | 501 | - | pre-feed | 10:00–24:00 | 2–3 mo | SM | ELISA | 4, 8 | - | - | 0.116 ± 0.112, ng/mg (raw values corrected per mg of protein per mL) |
| Joung et al. [67] | 2021 | 50 | C, M | post-feed, 24 h pooled | - | 7, 14, 21 and 28 d | WM | ELISA | 10 | 0.01 | - | - |
Data reported as mean ± SD or median (IQR) unless specified. AGA, appropriate age for gestational age; C, colostrum milk; CTL, control group; CI, confidence interval; CV, coefficient variation; d, day; ECIs, electrochemical immunosensor; EDTA, ethylenediaminetetraacetic acid; ELISA, enzyme-linked immunosorbent assay; GDM, gestational diabetes mellitus; IRMA, immunoradiometric assay; LGA, large for gestational age; LOD, limit of detection; M, mature milk; mo, month; Non-Ob, without obesity; Ob, with obesity; R, recovery of analyte; RIA, radioimmunoassay; SGA, small for gestational age; SM, skim milk; SPATZ, Ulm SPARTZ health study; UBCS, Ulm birth cohort study; wk, week; WM, whole milk; y, year.