Diabetes types as well as the impaired

Diabetes types 2 as well as the impaired fasting glucose (IFG) are common among Jordanian population. The estimated age standardized prevalence rate of (IFG) and diabetes were 7.8% and 17.1%, respectively, with no significant gender differences according to a recent study (Ajlouni et al., 2008). To complicate things further, there are alarming rates of obesity and its associated co-morbidities among Jordanians, especially among women (Khader et al., 2008). This study aims to evaluate the serum levels of adiponectin in type 2 diabetic patients and to establish a correlation between adiponectin serum levels and insulin resistance in those patients. In contrast, previous studies had investigated the association of adiponectin serum levels and obesity and DM type 2. Jordan is an ideal place to conduct the current study due to the high prevalence of DM type 2 and prediabetes, as mentioned earlier.


The clinical and demographic characteristics of the study population are presented in Table 1. In the study population, diabetic patients had lower adiponectin serum level compared to non-diabetics control group. However, statistically this difference was not significant (Fig. 1A).

Females had a significantly higher adiponectin serum levels than males. A possible explanation for this gender based difference in adiponectin serum levels might be due to the following reasons; first, is the effect of sex hormones on the production of adiponectin rate (Kadowaki et al., 2006). Experimental studies have proved that androgens have an inhibitory effect on adiponectin secretion (Bottner et al., 2004; Nishizawa et al., 2002). Second, is the different body fat distribution between males and females. It has been reported that the number of fat Calcium Ionophore I and their size are possible determinants of adiponectin production rates since it is mainly secreted from adipocytes (Cnop et al., 2003).
It is known that insulin resistance increases with age, which would predict the lower adiponectin levels in the elderly (Cnop et al., 2003). Interestingly, our study has shown that the adiponectin levels were correlated positively with age. The increase in adiponectin levels with age could be explained by the fact that the decline in sex steroidal hormones with age might rise the adiponectin levels in the elderly (Bottner et al., 2004; Nishizawa et al., 2002). Moreover, the decline in renal function with aging might reduce the adiponectin clearance by kidney (Isobe et al., 2005).
Generally, obesity is associated with insulin resistance (Cnop et al., 2002). Abdominal obesity, where the fat is centrally distributed, is particularly an important determinant of insulin resistance (Cnop et al., 2003; Gierach et al., 2014). It has been reported that abdominal obesity, measured by waist circumferences, is strongly associated with lower levels of adiponectin and decrease in insulin sensitivity among diabetic patients (Cnop et al., 2003; Mohammadzadeh and Ghaffari, 2014).
This study has shown low levels of adiponectin in both obese diabetic patients and patients with abdominal obesity and negative correlation between adiponectin levels and both BMI and WC. Given the fact that adiponectin is a major modulator of insulin action for its role in enhancing insulin sensitivity (Cnop et al., 2003; Schulze et al., 2004), it is therefore of critical importance to note that factors decreasing adiponectin levels such as obesity, and specially the abdominal obesity, could correlate with insulin resistance.
In addition, diabetic patients included in this study had a variable adiponectin serum levels. The majority of them had levels between (1.02–6.9)μg/ml while the remaining had levels ⩾7μg/ml. This variability in adiponectin serum levels might indicate that there are some factors affect the adiponectin levels among type 2 diabetic patients. It is important to note that the majority of diabetic patients who have adiponectin levels ⩾7μg/ml were elderly, females, and had lower mean of BMI compared to the second group (Table.4). Taken together, these characteristics of diabetic patients who have adiponectin levels ⩾7μg/ml are possible factors for increasing adiponectin level in this subgroup of diabetic patients.