Weight gain and changes in plasma adiponectin and leptin concentrations after 12-month insulin intensive therapy for Chinese male patients with newly diagnosed type 2 diabetes

Impact of Weight Change in Adults with Type 2 Diabetes Mellitus: A Literature Review and Critical Analysis

Objective

Weight reduction is a key component of diabetes management in adults with type 2 diabetes mellitus (T2DM), yet the benefits of weight loss in T2DM patients have been difficult to quantify. We examined the medical literature regarding the relationships between weight change and 1) glycemic control and 2) cost and resource use.

Methods

Systematic searches were conducted in the electronic databases Embase, MEDLINE, and the Cochrane Database of Systematic Reviews to identify publications regarding the impact of weight change on T2DM outcomes from 2007 onward. Identified publications were screened for relevance against predefined eligibility criteria, and methodological approaches and results were extracted. Evidence for the impact of weight change on outcomes was evaluated and used to identify strengths, limitations, and gaps in the current literature.

Results

The number of studies meeting eligibility criteria for each outcome was: glycemic control (n=38) and cost and resource use (n=11). The relationship between weight change and glycemic control was dependent on the interplay of multiple factors, eg, the weight loss interventions employed, the antidiabetic medication classes used, the time horizon, and baseline BMI and glycemic control. With respect to cost and resource use, the review indicated that savings were associated with weight loss, and increased costs were associated with weight gain.

Conclusion

Studies regarding weight change in T2DM patients demonstrated varying effects on glycemic control and a positive association with costs and resource use, where weight loss was associated with decreased costs and resource use. Future studies may be able to clarify these relationships.

Prospective Study of Long-Term Interrelationships Among Adiposity-Associated Biomarkers in Women

OBJECTIVE

This study aimed to investigate the prospective interrelationships among biomarkers that may provide mechanistic insights into obesity-related diseases.

METHODS

A total of 850 women in the Nurses' Health Study II with two fasting blood measurements (1996-1999 and 2010-2011) of adiponectin, leptin, soluble leptin receptor, insulin, retinol-binding protein 4, high-sensitivity C-reactive protein (hsCRP), and interleukin-6 were included. Biomarker interrelationships were examined in the following three ways: (1) cross-sectional associations at baseline and follow-up, (2) longitudinal associations of concurrent biomarker changes, and (3) prospective associations of each baseline biomarker with other biomarker changes.

RESULTS

In cross-sectional analyses, most biomarkers were correlated after multivariable adjustment including BMI, with the strongest correlations observed between leptin and insulin and between hsCRP and interleukin-6. In longitudinal analyses, similar results were observed after multivariable adjustment including weight change. However, in prospective analyses, only three associations observed in cross-sectional and longitudinal analyses were consistently significant (P < 0.05). Every doubling in baseline adiponectin was associated with -9.0% insulin change. The corresponding estimate was 9.3% for baseline leptin and hsCRP change and 3.1% for baseline hsCRP and leptin change.

CONCLUSIONS

Baseline adiponectin concentrations were inversely associated with subsequent insulin change, whereas baseline leptin concentrations were positively associated with hsCRP change and vice versa.

Serum leptin, resistin, and adiponectin levels in obese and non-obese patients with newly diagnosed type 2 diabetes mellitus: A population-based study

Disturbances in adipocytokine profiles can contribute to peripheral insulin resistance and impairment of insulin production, which are 2 primary pathophysiological mechanisms involved in type 2 diabetes mellitus (T2DM). Previous studies of disturbed adipocytokine profiles have resulted in ambiguous findings; therefore, we conducted the current study comparing leptin, resistin, and adiponectin concentrations in patients with newly diagnosed T2DM who had normal body mass index (BMI) and those who were obese.We studied a population-based cohort of healthy participants and those with newly diagnosed T2DM. A normal BMI group was randomly selected; age- and sex-matched obese participants were recruited. Circulating leptin, resistin, and adiponectin concentrations were measured and compared between groups using analysis of variance; binary logistic regression analysis was then performed to compare the normal BMI and obese groups.In total, 85 healthy participants and 38 patients with diabetes (19 with normal BMI and 17 who were obese) were enrolled. After adjustment for BMI and waist circumference, the median leptin concentration was higher in the obese group (6.77 (3.89-10.73) ng/mL) than in the normal BMI group (1.69 (0.80-3.89) ng/mL) (P = .007), whereas the median adiponectin concentration was lower in the obese group (1.03 (0.75-2.36) μg/mL vs 3.36 (0.59-7.63) μg/mL, P = .03). In addition, the adiponectin/leptin ratio was higher in the normal BMI group (145.6 (41.3-495.9) ng/mL) than in the obese group (20.55 (8.74-36.94) ng/mL, P = .002).Compared with the normal BMI T2DM group, the obese T2DM group exhibited a disturbed adipocytokine profile in the form of a significantly increased leptin concentration and reduced adiponectin level. Further studies are needed to determine the causal relationship for this difference and evaluate its importance for personalized diabetic treatment.

Adipokines in hereditary breast cancer patients and healthy relatives

Background

The role of adipocytokines and ghrelin in hereditary breast cancer syndrome (HBCS) has never been tested.

Results

No significant differences in leptin, adiponectin and ghrelin plasma levels between cancer patients and healthy subjects was observed. Conversely, an higher level of adiponectin was shown in healthy subjects with BRCA 1/2 gene mutation vs those without (p < 0.03). Logistic regression analysis demonstrated that Adiponectin plasma level (OR 0.26; 95% CI:0.007–0.81; p < 0.02) and age (OR 5.51; 95% CI:1.78–19.71; p < 0.004) were the only factors independently associated with BMI; furthermore, Leptin plasma level (OR 0.23; 95% CI:0.06–0.76; p < 0.01) and age (OR 0.05; 95% CI:0.05–0.61; p < 0.007) resulted the only factors significantly associated with breast cancer.

Materials and Methods

We analyzed blood plasma expression of leptin, adiponectin and ghrelin using Bio-Plex platform in 25 breast cancer patients with HBCS and in 38 healthy relatives. BRCA 1/2 gene status (presence of pathogenic mutations by direct molecular sequencing), clinical-pathological characteristics and Body Mass Index (BMI) of each subject were recorded.

Conclusions

Adiponectin confirms to be associated with BMI also in subjects with HBCS. Leptin plasma level seems a direct and independent biomarker of a breast cancer risk. A validation of Leptin as a circulating biomarker of breast cancer development in larger series of HBCS subjects is needed.

Insulin upregulates betatrophin expression via PI3K/Akt pathway

Betatrophin is regarded as a liver-produced hormone induced by insulin resistance (IR). However, it remains largely unknown how IR regulates betatrophin expression. To study whether IR could regulate betatrophin expression and the corresponding molecular mechanisms, betatrophin levels were examined in 6 in vitro IR models which were established using human hepatocytes L02 with different agents, including tumor necrosis factor-α, interleukin-1β, dexamethasone, palmitate, high glucose and insulin and betatrophin levels were elevated only in the insulin group. These results suggest that it is insulin, not IR that promotes betatrophin expression. In the meantime, PI3K/Akt pathway was activated by insulin and suppressed by above agents that caused IR. Insulin-upregulated betatrophin expression was suppressed by PI3K/Akt inhibitors and IR, suggesting that insulin upregulates and IR decreases betatrophin production through PI3K/Akt pathway. Consistently, the treatment of insulin in mice dose-dependently upregulated betatrophin levels, and the administration of metformin in IR mice also stimulated betatrophin production since published study showed metformin improved PI3K/Akt pathway and IR. In humans, compared with those without insulin treatment, serum betatrophin levels were increased in type 2 diabetic patients with insulin treatment. In conclusion, insulin stimulates betatrophin secretion through PI3K/Akt pathway and IR may play an opposite role.