Circulating Preprandial Ghrelin to Obestatin Ratio Is Increased in Human Obesity

Abstract

Circulating preprandial ghrelin to obestatin ratio is elevated in human obesity. We suggest that high preprandial ghrelin to obestatin ratio may be involved in the etiology and pathophysiology of obesity.

Circulating obestatin levels and the ghrelin/obestatin ratio in obese women

“…In this study, we confirmed that circulating ghrelin concentrations are lowered in the obese state, as previously reported (23), but an additional finding is that the ghrelin/obestatin ratio was lower in obese subjects than in normal-weight controls, which contrasts with the higher values reported by Guo et al (13) in Chinese obese individuals. Despite the fact that this discrepancy cannot be resolved without additional more detailed studies, these findings seem to support the concept that disparate post-translational cleavage of preproghrelin into these two sibling peptides may be regulated differently in the presence of obesity or, alternatively, that the common regulatory factors are responsible for these still poorly defined coordinate changes of the ghrelin and obestatin system according to the nutritional status.…”

“…Despite the fact that this discrepancy cannot be resolved without additional more detailed studies, these findings seem to support the concept that disparate post-translational cleavage of preproghrelin into these two sibling peptides may be regulated differently in the presence of obesity or, alternatively, that the common regulatory factors are responsible for these still poorly defined coordinate changes of the ghrelin and obestatin system according to the nutritional status. This is further emphasized by the finding of Guo et al (13) that the ghrelin/obestatin ratio was decreased after a morning mixed meal in both normal-weight and obese individuals, with a disappearance following the meal of the difference in the ghrelin/obestatin ratio between the two groups, further emphasizing the importance of the nutritional status on ghrelin and obestatin.…”

“…These findings are not, however, concordant with the data reported in the few studies performed so far. In fact, Hainer et al (12) and, more recently, Guo et al (13) found that obese subjects had lower rather than higher circulating levels when compared with normal-weight subjects. Based on available data, it is difficult to explain these disparate findings.…”

“…Obestatin levels have been demonstrated to be lower in obese subjects when compared with lean subjects, showing a significant increase in the obese patients 6 months after gastric banding surgery (12). Accordingly, in a more recent study, Guo et al (13) found that ghrelin and obestatin levels were lower but their ratio was higher in a mixed group of obese males and females, compared with their normal-weight counterparts, which raises some interesting points on the pathophysiological relevance of balance of these two peptides in obesity and related metabolic disorders.…”

Ghrelin Gene Products in Acute and Chronic Inflammation

“…Circulating obestatin concentrations have been reported to be either reduced (Anderwald-Stadler et al 2007;Nakahara et al 2008) or, more frequently, increased (Guo et al 2007;Prodam et al 2011;Reinehr et al 2008;Vicennati et al 2007) in obesity. Based on available data, it is difficult to explain these contrasting findings that seem to depend mainly on sample size, age, and ethnicities.…”