The Physiologic Effects of Intranasal Oxytocin on Sarcopenic Obesity

The Physiologic Effects of Intranasal Oxytocin on Sarcopenic Obesity

Obesity is highly prevalent in older adults and is a major cause of sarcopenia and disability in older adults. Although exercise can counteract the effects of obesity and sarcopenia, many have difficulty adhering to an exercise program and the benefits of exercise are variable. Therefore, there is an urgent need to test novel pharmacologic interventions to prevent disability and loss of independence. Oxytocin is a pituitary hormone released during parturition and lactation that is also known to suppress appetite in rodents and humans; and, recent small studies have found that intranasal oxytocin reduces body weight in adults. We propose a pilot study of intranasal oxytocin as a novel approach to promote weight loss and increase muscle mass in older subjects with sarcopenic obesity.

The pilot study will be conducted at 3 sites in 9 visits over a period of 12+ weeks. Older sedentary subjects will be screened for sarcopenic obesity using a modified consensus definition and evaluated at baseline for safety labs, glucose tolerance, body composition, cognition and physical performance, as well as systemic inflammatory markers in blood and muscle tissue.

Eligible subjects self-administer 24 IU intranasal oxytocin four times a day for 8 weeks.

The study will examine whether the intervention will promote weight loss and preserve muscle mass, thereby preserving and/or improving physical function in older subjects with sarcopenic obesity.

Generalized linear mixed effects model will be used to evaluate the effect of oxytocin on the change of each continuous measure. The effect of oxytocin will be assessed by whether the time by oxytocin interaction is significantly different from 0 with a 2-sided p-value<0.05.

Inclusion Criteria:

• BMI 30-40 kg/m2
• Sedentary (< 2 strenuous exercise/week)
• Gait speed < 1 meter/second

Exclusion Criteria:

• Diabetes (ADA criteria)
• Heart disease (MI or New York Heart Classification grade III-IV)
• Poorly controlled hypertension (SBP > 170 or DBP >95 mm/Hg)
• Anemia (Hematocrit <34%)
• Renal Disease (Serum Creatinine >1.4, abnormal serum sodium levels, abnormal urinalysis, or physical exam findings indicative of fluid imbalance; individuals with underlying disorder of sodium/water balance, such as SIADH, diabetes insipidus, or psychogenic polydipsia)
• Liver Disease (AST/ALT/AlkPhos > 2x upper limit of normal)
• Use of systemic steroid, androgens, or anti-coagulants
• Active/unstable conditions: inflammatory, thyroid, autoimmune, gastrointestinal (GI), hematologic, or neoplastic disorders
• Individuals with underlying seizure disorder or underlying neurologic disorder that increases seizure risk
• Cognitive impairment (MiniCog <3), unstable mental illness, substance abuse, or history of eating disorder