Low-molecular-weight adiponectin is more closely associated with episodes of asthma than high-molecular-weight adiponectin

Abstract

Adiponectin plays various rolls in energy metabolism [1], lipid metabolism [2][3][4] and appestat regulation [5]. It has also attracted considerable attention regarding its anti-inflammatory activities, including inhibiting immune responses in macrophages [6,7]. Adiponectin activates AMP kinase, resulting in decreased NF-κb activity and decreased levels of CRP mRNA and proteins [8]. However, Schaffler et al. reported that increased adiponectin levels occur concomitantly with inflammatory responses [9]. They activated two monocytic cell lines with adiponectin and analyzed the subunit of NF-κb in different leukocyte cell lines [10].Low-molecular-weight adiponectin is more closely associated with episodes of asthma than high-molecularweight adiponectin Yuuki Matsumoto 1) , Kouji Toyomasu 2) , Naohisa Uchimura 3) and Tatsuya Ishitake Abstract. Adiponectin is divided into high-molecular-weight (HMW), middle-molecular-weight (MMW) and lowmolecular-weight (LMW) types. While HMW adiponectin has been studied by many researchers, the roles of MMW and LMW adiponectin have not yet been sufficiently elucidated. In addition, there are conflicting findings regarding the role of adiponectin in chronic inflammatory diseases, especially asthma. Therefore, we compared patients who suffered episodes of asthma in the past (=asthmatics) with those who did not (=non-asthmatics) in order to investigate the relationship between asthma and HMW, MMW and LMW adiponectin. The subjects in this study included 76 university students.None of the subjects were smokers, on regular medications or seeing a doctor regularly at the time. Fourteen subjects reported past histories of asthma. We also measured and compared the levels of leptin and ghrelin to that of adiponectin, as these hormones are connected with inflammatory conditions. Although the physical data of the asthmatics were similar to those of the non-asthmatics, the levels of ghrelin and all fractions of adiponectin tended to be lower in the asthmatics than in the non-asthmatics. While the levels of MMW and LMW adiponectin in the asthmatics were found to be significantly low, the levels of ghrelin and HMW adiponectin were not clear. According to a multivariate regression analysis of the MMW and LMW adiponectin levels, asthma was found to be more significantly associated with the LMW adiponectin level than age, waist circumference or HDL-C. The results suggest that LMW adiponectin may be associated with episodes of asthma in males. Keywords

Association of serum adiponectin with asthma and pulmonary function in the Japanese population

“…The average duration of asthma and the percentage of subjects who received inhaled steroids among the asthmatic subjects were 16.7 ± 14.4 cantly associated with "current asthma." A previous report regarding the LMW adiponectin-asthma association demonstrated that the level of LMW adiponectin was significantly lower among subjects who had experienced episodes of asthma [35], and these results were different from our findings in that the levels of LMW adiponectin were significantly higher among the subjects with current asthma. This discrepancy may have been caused by the difference in study subjects (past asthma vs. current asthma).…”

“…This discrepancy may have been caused by the difference in study subjects (past asthma vs. current asthma). However, in the previous study [35], when they analyzed the multivariate regression analysis, they treated the LMW adiponectin level as a dependent variable and the presence or absence of asthma episodes as an independent variable, respectively, and showed that the regression coefficient was 0.098 (SE, 0.033; P = 0.004), suggesting that LMW adiponectin was positively correlated with a history of asthma episodes. In other words, we believe that their results show that LMW adiponectin was higher among subjects with a history of asthma episodes than among To date, although several reports have examined the correlation between asthma and serum adiponectin levels, these studies have measured only the total adiponectin level and have not investigated the association between asthma and the various isoforms of adiponectin (HMW, MMW and LMW) [7][8][9][10][11][12][13][14][15][16][17].…”

“…However, literature regarding the total adiponectin-asthma association in humans is conflicting and confusing. To our knowledge, 12 studies using human adult subjects have analyzed the association between serum total adiponectin and the risk of asthma, independent of obesity [7][8][9][10][11][12][13][14][15][16][17]35] (Table 7); of these studies, 6 have shown significant associations [7][8][9][10]14, adiponectin, we speculated that the lower MMW/total ratio might be associated with asthma via a different mechanism from that involving LMW adiponectin. To our regret, in group 1, we only examined the association of total adiponectin with pulmonary function and did not examine the associations of the three adiponectin isoforms with pulmonary functions.…”

“…In the subjects in group 2, the three adiponectin fractions (HMW, MMW, and LMW) were measured using an ELISA (SEKISUI Medical Co Ltd, Japan) [35,36]. This ELISA had a dynamic range of 0.075-4.8 ng/mL.…”

“…In other words, we believe that their results show that LMW adiponectin was higher among subjects with a history of asthma episodes than among To date, although several reports have examined the correlation between asthma and serum adiponectin levels, these studies have measured only the total adiponectin level and have not investigated the association between asthma and the various isoforms of adiponectin (HMW, MMW and LMW) [7][8][9][10][11][12][13][14][15][16][17]. To the best of our knowledge, only one group has recently examined the associations between the three adiponectin isoforms (HMW, MMW, and LMW) and asthma episodes among male university students who had suffered episodes of asthma in the past but were not receiving medication for asthma at the time of examination; the authors reported that LMW adiponectin was significantly associated with a history of asthma episodes [35]. However, the authors did not examine the levels of adiponectin isoforms among subjects who were currently suffering from asthma.…”