This is a pilot and feasibility study to examine a novel intervention using leptin in
weight-reduced individuals who have undergone bariatric surgery but still remain obese.
Leptin, a peptide hormone secreted from adipose tissue, is a regulator of food intake and
energy expenditure. Administration of leptin resulted in profound weight reduction in the
few reported cases of obese individuals with genetic leptin deficiency. However, most obese
people have increased leptin levels. Such individuals are said to be in a
"leptin-resistant" state, whereby administration of physiological concentrations of leptin
are ineffective at producing significant weight reduction. Roux-en-Y gastric bypass surgery
(RYGBP) is more effective than diet alone in producing long-term reduction of body weight.
Yet even after surgery there is a plateau in weight loss though the individual may still be
obese and have or be at risk for obesity related morbidities. The investigators have shown
that plasma leptin levels are significantly lower in women after RYGBP compared with
BMI-matched controls. This state of relative hypoleptinemia or leptin insufficiency
suggests that post-RYGBP individuals may be in a "leptin-sensitive" state and, thus, would
undergo further weight loss when administered doses of leptin that would not normally result
in significant weight reduction. This study will examine the effects of leptin administered
by self-injection twice per day on body weight and endocrine function. All individuals will
received leptin and placebo and different times during the 34 week study period.
- Women only.
- Must have had Roux-en-Y gastric bypass 18 months to 10 years ago.
- Current BMI between 28 to 44.
- Must live in the vicinity of New York City to comply with 11 study visits over 34
- Must be willing to self-inject study drug twice per day.
- History of plastic surgery.