Introduction: Food reward stimuli elevate dopamine levels in brain reward circuits. Decreased dopaminergic signalling may be involved in pathophysiological processes leading to obesity and D2 receptor antagonists (antipsychotics) are associated with a higher risk of obesity. One study has demonstrated an association between the use of a dopamine D2 agonist (bromocriptine) and weight-loss in patients with prolactinoma. We have investigated the effect of cabergoline on body weight in a population presenting with hyperprolactinaemia.
Methods: One hundred medical records were studied. All patients had been evaluated for prolactin excess with a cannulated prolactin study. Macroprolactinaemia was excluded in all samples. Patients with panhypopitutiarism or previously treated with another dopamine agonist were excluded. Data was also unavailable in 3 patients, leaving 89 patients. Weight and cabergoline dose was recorded at each visit.
Results: (mean±S.E.M.). At Visit 1, prolactin was 1614.4±447.8 mU/l in cabergoline group (CG) and 534.1±75.8 mU/l in controls (P<0.001). Body weight and BMI at the first visit was 72.5±13.7 kg and 27.0±6.5 kg/m2 in CG and 70.6±9.0 kg and 26.9±1.1 kg/m2 in controls (P=NS). Cabergoline dose was 493.2±15.4 μg/week.
|Visit 1 (pre-treatment)||Visit 2||Visit 3||Visit 4|
|Days since first visit||NA||NA||166.4±33.3||168.05±21.2||329.3±67.2||345.2±75.3||511.4±161.7||540.2±170.8|
|Change in weight from first visit (kg)||NA||NA||−0.50±0.10*||+0.8±0.09||−0.3±0.06*||+1.8±0.4||−0.4±0.1*||+2.7±0.9|
|*P<0.05 compared to control.|
Conclusion: Cabergoline is unlikely to be considered as a useful weight loss agent, but in this study it was associated with weight stability compared to the weight gain that occurred amongst individuals who did not start dopamine agonist treatment.