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営業時間、予約なし診療およびご予約。4 - 5 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Serum or plasma
0.5 mL
0.2 mL (Note: This volume does not allow for repeat testing.)
Red-top tube, gel-barrier tube, or lavender-top (EDTA) tube
Transfer serum or plasma from cells and transfer to a plastic transport tube.
Room temperature
Temperature | Period |
---|---|
Room temperature | 14 days |
Refrigerated | 30 days |
Frozen | 21 days |
Freeze/thaw cycles | Stable x3 |
Gross lipemia; gross hemolysis
Measurement of leptin levels in serum or plasma
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Obesity is not generally caused by leptin deficiency, neither mutations of the leptin gene or the leptin receptor gene are frequent in humans, but leptin levels are commonly higher in subjects with obesity, and insensitivity to endogenous leptin is a hallmark of most cases of human obesity.1
Enzyme immunoassay (EIA)
See tables.2
BMI | Tanner Stage 1−2 | Tanner Stage 3−4 | Tanner Stage 5 |
---|---|---|---|
11 | 0.3−1.5 | 0.4−1.3 | 0.7−2.7 |
12 | 0.4−1.9 | 0.5−1.6 | 0.8−3.2 |
13 | 0.5−2.4 | 0.7−2.1 | 0.9−3.7 |
14 | 0.6−3.1 | 0.8−2.6 | 1.0−4.3 |
15 | 0.8−3.9 | 1.1−3.3 | 1.2−5.0 |
16 | 1.1−5.0 | 1.3−4.2 | 1.4−5.8 |
17 | 1.4−6.5 | 1.7−5.3 | 1.6−6.7 |
18 | 1.7−8.3 | 2.1−6.7 | 1.9−7.8 |
19 | 2.2−10.7 | 2.7−8.5 | 2.2−9.1 |
20 | 2.9−13.7 | 3.4−10.7 | 2.6−10.5 |
21 | 3.7−17.6 | 4.3−13.6 | 3.0−12.3 |
22 | 4.7−22.6 | 5.5−17.2 | 3.5−14.2 |
23 | 6.0−29.0 | 6.9−21.8 | 4.0−16.6 |
24 | 7.8−37.2 | 8.8−27.6 | 4.7−19.3 |
25 | 10.0−47.8 | 11.1−34.9 | 5.5−22.4 |
26 | 12.8−61.4 | 14.0−44.2 | 6.4−26.0 |
27 | 16.4−78.8 | 17.7−56.0 | 7.4−30.3 |
28 | 21.5−101.0 | 22.5−70.9 | 8.6−35.2 |
29 | 27.0−130.0 | 28.4−89.7 | 10.0−40.9 |
30 | 36.0−114.0 | 11.6−47.6 | |
31 | 45.6−144.0 | 13.5−55.3 | |
32 | 57.7−144.0 | 15.7−64.4 | |
33 | 18.3−74.9 | ||
34 | 21.2−87.0 | ||
35 | 24.7−101.0 | ||
36 | 28.7−118.0 | ||
37 | 33.4−137.0 |
BMI | Tanner Stage 1−2 | Tanner Stage 3−4 | Tanner Stage 5 |
---|---|---|---|
11 | 0.1−0.7 | 0.1−0.6 | 0.1−0.5 |
12 | 0.2−0.9 | 0.1−0.7 | 0.1−0.5 |
13 | 0.2−1.2 | 0.1−0.9 | 0.1−0.6 |
14 | 0.3−1.6 | 0.1−1.1 | 0.1−0.7 |
15 | 0.4−2.0 | 0.1−1.3 | 0.1−0.8 |
16 | 0.5−2.7 | 0.2−1.6 | 0.1−1.0 |
17 | 0.6−3.5 | 0.2−2.0 | 0.1−1.1 |
18 | 0.8−4.6 | 0.2−2.5 | 0.2−1.3 |
19 | 1.0−6.0 | 0.3−3.0 | 0.2−1.5 |
20 | 1.4−7.9 | 0.3−3.7 | 0.2−1.7 |
21 | 1.8−10.4 | 0.4−4.6 | 0.2−2.0 |
22 | 2.3−13.6 | 0.5−5.6 | 0.3−2.3 |
23 | 3.1−17.8 | 0.6−6.9 | 0.3−2.7 |
24 | 4.0−23.3 | 0.8−8.5 | 0.4−3.1 |
25 | 5.2−30.6 | 1.0−10.5 | 0.4−3.6 |
26 | 6.9−40.1 | 1.2−12.9 | 0.5−4.2 |
27 | 9.0−52.5 | 1.5−15.8 | 0.6−4.8 |
28 | 11.8−68.9 | 1.8−19.4 | 0.6−5.6 |
29 | 15.5−90.3 | 2.2−23.9 | 0.7−6.5 |
30 | 20.3−118.0 | 2.7−29.4 | 0.9−7.5 |
31 | 3.3−36.2 | 1.0−8.7 | |
32 | 4.1−44.5 | 1.2−10.0 | |
33 | 5.0−54.7 | 1.3−11.6 | |
34 | 6.2−67.2 | 1.5−13.4 | |
35 | 7.6−82.6 | 1.8−15.6 | |
36 | 9.4−101.0 | 2.1−18.0 | |
37 | 11.5−124.0 | 2.4−20.8 | |
38 | 2.8−24.1 | ||
39 | 3.2−27.9 | ||
40 | 3.7−32.3 |
BMI | Range | BMI | Range |
---|---|---|---|
11 | 0.7−3.6 | 24 | 4.4−24.2 |
12 | 0.8−4.2 | 25 | 5.1−28.0 |
13 | 0.9−4.8 | 26 | 5.9−32.4 |
14 | 1.0−5.6 | 27 | 6.8−37.5 |
15 | 1.2−6.5 | 28 | 7.9−43.5 |
16 | 1.4−7.5 | 29 | 9.1−50.4 |
17 | 1.6−8.7 | 30 | 10.6−58.3 |
18 | 1.8−10.0 | 31 | 12.2−67.5 |
19 | 2.1−11.6 | 32 | 14.1−78.2 |
20 | 2.4−13.4 | 33 | 16.4−90.5 |
21 | 2.8−15.6 | 34 | 19.0−105.0 |
22 | 3.3−18.0 | 35 | 22.0−121.0 |
23 | 3.8−20.9 | 36 | 25.4−141.0 |
BMI | Range | BMI | Range |
---|---|---|---|
11 | 0.1−0.4 | 25 | 1.1−9.6 |
12 | 0.1−0.6 | 26 | 1.3−12.0 |
13 | 0.1−0.7 | 27 | 1.6−14.9 |
14 | 0.1−0.9 | 28 | 2.0−18.6 |
15 | 0.1−1.1 | 29 | 2.5−23.2 |
16 | 0.2−1.3 | 30 | 3.2−28.9 |
17 | 0.2−1.7 | 31 | 3.9−36.0 |
18 | 0.2−2.1 | 32 | 4.9−44.9 |
19 | 0.3−2.6 | 33 | 6.1−55.8 |
20 | 0.4−3.2 | 34 | 7.6−69.6 |
21 | 0.4−4.0 | 35 | 9.5−86.7 |
22 | 0.5−5.0 | 36 | 11.8−108.0 |
23 | 0.8−6.2 | 37 | 14.8−135.0 |
24 | 0.9−7.7 |
Leptin is a 16-kilodalton protein that was first identified when it was cloned in 1994.3,4 Humans and mice with defects in the gene that codes for leptin, referred to as the obese or OB gene, tend to become morbidly obese.4 Obese mice with the ob/ob defect lose weight when treated with exogenous leptin.4 Leptin is primarily produced by the adipose tissue in proportion to the size of fat stores.4-7 Besides adipose tissue, leptin is also produced by other tissues, such as the stomach, placenta, and mammary gland.5
Leptin secreted by adipose tissue regulates energy homeostasis, neuroendocrine function, metabolism, immune function and other systems through its effects on the central nervous system and peripheral tissues.8-10 Increased leptin levels stimulate the central nervous system to reduce appetite and increase energy expenditure.4,5,7 Leptin is thought to play an important role in the body's response to food deprivation or starvation.7,8,11,12
Rare homozygous mutations in the leptin (LEP) gene can cause complete leptin deficiency that results in hyperphagia and severe early-onset obesity.13-15 Patients heterozygous for these mutations show partial leptin deficiency and increased body weight.16,17 Leptin administration has been shown to restore metabolic and neuroendocrine abnormalities in individuals with leptin-deficient states, including patients with congenital leptin deficiency generalized lipodystrophy, hypothalamic amenorrhea and lipoatrophy.13-15
Hyperleptinemia and resistance to reducing body mass are two characteristics of typical obesity.18,19 Strong positive associations exist between plasma leptin levels and body fat percentage.6 In obesity the efficacy of the anorexic effect of leptin is decreased with leptin resistance developing due to a defect in intracellular signaling associated with the leptin receptor or decreases in leptin transport across the blood–brain barrier.20 A decrease in tissue sensitivity to leptin leads is characterized by reduced satiety, overconsumption of nutrients, and increased total body mass and the development of metabolic disorders, such as insulin resistance and dyslipidemia.6,20,21
A role for leptin has been implicated in the control of angiogenesis, hematopoiesis, immunity and bone formation, and a number of other functions.4 Leptin is thought to play a role in normal sexual development and in reproduction.11,22 Humans and mice with genetic absence of leptin fail to complete puberty and increased leptin levels in mice lead to early puberty.11 Studies also suggest that leptin levels affect fertility in females and may be involved in the development of normal pregnancy.11,22 During pregnancy, the placenta produces leptin, and maternal circulating levels during the second and third trimesters are approximately twice the level of the non-pregnant state.11,22
Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
---|---|---|---|---|---|---|
146712 | Leptin, Serum | 21365-2 | 146713 | Leptin, Serum | ng/mL | 21365-2 |
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