1. Should everyone who is overweight have a leptin test performed?
Leptin testing is not routinely performed and is not indicated for most people. If someone is obese and has persistent hunger, or has a young child who is severely obese, then leptin testing may be considered.
2. How are classifications of body weight determined?
Classification is currently based on body mass index, or BMI.
For youth, weight and height as well as age and sex are considered in determining their BMI percentile. An overweight youth is one whose BMI is between the 85th percentile and the 94th percentile on standardized growth charts. An obese youth is one who is at or above the 95th percentile on standardized growth charts or has a BMI of greater than or equal to 30 kg/m2, whichever is lower.
For adults, BMI is calculated as:
BMI = (Weight in pounds) / (height in inches squared) x 703
In those with very rare inherited leptin deficiencies, replacement therapy has been successful in addressing obesity. However, there are insufficient data at this time to support its routine use for other leptin deficiencies.
Although leptin was the first adipocyte cytokine (or "adipokine") identified, many others have been discovered. The two that have been most extensively investigated are resistin, which increases insulin resistance, and adiponectin, which lowers it. Resistin is increased and adiponectin is decreased in obesity. They also have opposite effects on inflammation; resistin increases inflammation, while adiponectin decreases it. Another recently discovered adipokine is visfatin, which is elevated in type 2 diabetes and may play a role in elevating insulin levels. Several other adipokines are aplin, chemerin, and omentin, all of which appear to be anti-inflammatory.
This article was last reviewed on April 19, 2013. | This article was last modified on December 19, 2014.
The review date indicates when the article was last reviewed from beginning to end to ensure that it reflects the most current science. A review may not require any modifications to the article, so the two dates may not always agree.
The modified date indicates that one or more changes were made to the article. Such changes may or may not result from a full review of the article, so the two dates may not always agree.