Rheumatoid arthritis disease activity significantly impacts on the severity of interstitial lung disease.

OBJECTIVES: Rheumatoid arthritis (RA) related interstitial lung disease (ILD) impacts on the treatment strategy and its prognosis in patients with RA. However, the relationship between RA disease activity and the severity of comorbid ILD has not been fully investigated. This study aimed to investigate the impact of RA disease activity on the severity of comorbid ILD in detail based on currently established visual scoring method along with physiological severity. METHODS: Consecutive patients with RA visiting to our Rheumatology Centre between December 2020 and December 2023 were analysed. The radiological severity of ILD was evaluated by averaging the extent of the combined lesion of ground glass opacity, reticulation and honeycombing in 5% increments in six representative high-resolution computed tomography slices ranging from 0% (no involvement) to 100% (all lung fields affected) according to Goh and Walsh's method. Associations between the radiological and physiological severity of ILD and patients' features were investigated using linear regression analysis. RESULTS: Among 124 patients (32 men, 92 women), the median age was 70 years, and the median disease duration was 2.92 years. Radiological severity of ILD was 0% (without ILD) in 107 (86.2%), ILD with extent < 10% in nine (7.2%), ILD with extent ≥10% and < 20% in three (2.4%), ILD with extent ≥20% in five (4.0%). Both disease activity score (DAS)28-erythrocyte sedimentation rate (ESR) (standardized coefficient = 0.199, P = 0.03) and rheumatoid factor titre (standardized coefficient = 0.247, P = 0.01) were significantly associated with the radiological quantitative severity of ILD in multivariate analysis adjusted for age, sex, disease duration, smoking status and anti-citrullinated peptide antibody titre. DAS28-ESR was significantly associated with forced vital capacity% predicted (standardized coefficient = -0.230, P = 0.047). CONCLUSIONS: Disease activity of RA was significantly associated with the severity of RA-ILD both radiologically and physiologically.

Associating the Severity of Emphysema with Coronary Flow Reserve and Left Atrial Conduit Function for the Emphysema Patients with Known or Suspected Coronary Artery Disease.

PURPOSE: Pulmonary emphysema may associate with ischemic heart disease through systemic microvascular abnormality as a common pathway. Stress cardiovascular MR (CMR) allows for the assessment of global coronary flow reserve (CFR). The purpose of this study was to evaluate the association between the emphysema severity and the multiple MRI parameters in the emphysema patients with known or suspected coronary artery disease (CAD). METHODS: A total of 210 patients with known or suspected CAD who underwent both 3.0T CMR including cine CMR, stress and rest perfusion CMR, stress and rest phase-contrast (PC) cine CMR of coronary sinus, and late gadolinium enhancement (LGE) CMR, and lung CT within 6 months were studied. Global CFR, volumes and functions of both ventricles and atria, and presence or absence of myocardial ischemia and infarction were evaluated. Emphysema severity was visually determined on lung CT by Goddard method. RESULT: Seventy nine (71.0 ± 7.9 years, 75 male) of 210 patients with known or suspected CAD had emphysema on lung CT. Goddard score was significantly correlated with CFR (r = -0.246, P = 0.029), left ventricular end-diastolic volume index (LV EDVI) (r = -0.230, P = 0.041), right ventricular systolic volume index (RV SVI) (r = -0.280, P = 0.012), left atrial (LA) total emptying volume index (r = -0.269, P = 0.017), LA passive emptying volume index (r = -0.309, P = 0.006), LA systolic strain (Es) (r = -0.244, P = 0.030), and LA conduit strain (Ee) (r = -0.285, P = 0.011) in the patients with emphysema. Multiple linear regression analysis revealed LA conduit function was independently associated with emphysema severity as determined by Goddard method (beta = -0.361, P = 0.006). CONCLUSION: LA conduit function independently associates with emphysema severity in the emphysema patients with known or suspected CAD after adjusting age, sex, smoking, and the CMR indexes including CFR. These findings suggest that impairment of LA function predominantly occurs prior to the reduction of the CFR in the emphysema patients with known or suspected CAD.

The value of Bayesian penalized likelihood reconstruction for improving lesion conspicuity of malignant lung tumors on 18F-FDG PET/CT: comparison with ordered subset expectation maximization reconstruction incorporating time-of-flight model and point spread function correction.

OBJECTIVE: To evaluate the value of Bayesian penalized likelihood (BPL) reconstruction for improving lesion conspicuity of malignant lung tumors on 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography computed tomography (PET/CT) as compared with the ordered subset expectation maximization (OSEM) reconstruction incorporating time-of-flight (TOF) model and point-spread-function (PSF) correction. METHODS: Twenty-nine patients with primary or metastatic lung cancers who underwent 18F-FDG PET/CT were retrospectively studied. PET images were reconstructed with OSEM + TOF, OSEM + TOF + PSF, and BPL with noise penalty strength ß-value of 200, 400, 600, and 800. The signal-to-noise ratio (SNR) was determined in normal liver parenchyma. Lung lesion conspicuity was evaluated in 50 lung lesions by using a 4-point scale (0, no visible; 1, poor; 2, good; 3, excellent conspicuity). Two observers were independently asked to choose the most preferred reconstruction for detecting the lung lesions on a per-patient level. The maximum standardized uptake value (SUVmax) was measured in each of the 50 lung lesions. RESULTS: Liver SNR on the images reconstructed by BPL with ß-value of 600 and 800 (17.8 ± 3.7 and 22.5 ± 4.6, respectively) was significantly higher than that by OSEM + TOF + PSF (15.0 ± 3.4, p < 0.0001). BPL with ß-value of 600 was chosen most frequently as the preferred reconstruction algorithm for lung lesion assessment by both observers. The conspicuity score of the lung lesions < 10 mm in diameter on images reconstructed by BPL with ß-value of 600 was significantly greater than that with OSEM + TOF + PSF (2.2 ± 0.8 vs 1.6 ± 0.9, p < 0.0001), while the conspicuity score of the lesions ≥ 10 mm in diameter was not significantly different between BPL with ß-value of 600 and OSEM + TOF + PSF. The mean SUVmax was increased by BPL with ß-value of 600 for the lung lesions with < 10 mm in diameter, compared to OSEM + TOF + PSF (3.4 ± 3.1 to 4.2 ± 3.5, p = 0.001). In contrast, BPL with ß-value of 600 did not provide increased SUVmax for the lesions ≥ 10 mm in diameter. CONCLUSION: BPL reconstruction significantly improves the detection of small inconspicuous malignant tumors in the lung, improving the diagnostic performance of PET/CT.

Usefulness of dictionary learning-based processing for improving image quality of sub-millisievert low-dose chest CT: initial experience.

PURPOSE: To develop a dictionary learning (DL)-based processing technique for improving the image quality of sub-millisievert chest computed tomography (CT). MATERIALS AND METHODS: Standard-dose and sub-millisievert chest CT were acquired in 12 patients. Dictionaries including standard- and low-dose image patches were generated from the CT datasets. For each patient, DL-based processing was performed for low-dose CT using the dictionaries generated from the remaining 11 patients. This procedure was repeated for all 12 patients. Image quality of normal thoracic structures on the processed sub-millisievert CT images was assessed with a 5-point scale (5 = excellent, 1 = very poor). Lung lesion conspicuity was also assessed on a 5-point scale. RESULTS: Image noise on sub-millisievert CT was significantly decreased with DL-based image processing (48.5 ± 13.7 HU vs 20.4 ± 7.9 HU, p = 0.0005). Image quality of lung structures was significantly improved with DL-based method (middle level of lung, 2.25 ± 0.75 vs 2.92 ± 0.79, p = 0.0078). Lung lesion conspicuity was also significantly improved with DL-based technique (solid nodules, 3.4 ± 0.6 vs 2.7 ± 0.6, p = 0.0273). CONCLUSION: Image quality and lesion conspicuity on sub-millisievert chest CT images may be improved by DL-based post-processing.

Endobronchial brachytherapy with curative intent: the impact of reference points setting according to the bronchial diameter.

Endobronchial brachytherapy (EBB) is an effective treatment for endobronchial tumors. However, bronchial toxicity caused by over-irradiation remains problematic. To decrease bronchial toxicity, we developed a source-centralizing applicator for EBB. The purpose of the present study was to assess the efficacy and safety of EBB with varying reference dose points according to the bronchial diameter, using a source-centralizing applicator. We reviewed 15 patients with endobronchial carcinoma who were treated with curative intent using a combination of external beam radiotherapy (EBRT) and high-dose-rate EBB between 2005 and 2014. During each EBB session, we used a source-centralizing applicator that maintained the source-delivering catheter in the center of the bronchial lumen. Reference dose points were 5-7 mm from the source axis, depending on the bronchial diameter. The median radiation doses of EBRT and EBB were 40 Gy in 20 fractions and 18 Gy in 3 fractions, respectively. The median observation period was 36 months. The 3-year overall survival, progression-free survival and local control rates were 79%, 77% and 100%, respectively. Grade 2 radiation pneumonitis was observed in two cases. Bronchial toxicities, such as hemoptysis or the symptoms of chronic bronchitis, were not observed. EBB with varying reference dose points according to bronchial diameter, using a source-centralizing applicator, is a promising procedure that may be effective for tumor elimination and reducing toxicity to the bronchial wall.

[A case of spectacular shrinking deficit caused by paradoxical cerebral embolism secondary to pulmonary arteriovenous fistula].

We report a case of spectacular shrinking deficit caused by paradoxical cerebral embolism through pulmonary arteriovenous fistula (AVF). A 79-year-old female suddenly developed right hemiplegia, paresthesia, and speech disturbance symptoms that were improved within 20 min, indicating a diagnosis of spectacular shrinking deficit. Brain magnetic resonance imaging revealed acute cerebral infarcts in the left parietal cortex of the left middle cerebral arterial territory. A contrast-enhanced chest computed tomography scan revealed a pulmonary AVF in the middle lobe of the right lung. The patient had deep venous thrombosis in her left lower leg. She had no clinical signs of telangiectasia, did not exhibit recurrent epistaxis, and had no family history of hereditary hemorrhagic telangiectasia (HHT). Therefore, she was diagnosed with paradoxical cerebral embolism secondary to the pulmonary AVF without HHT. Pulmonary AVF should be considered in patients with cerebral embolism, even when presenting with spectacular shrinking deficit.

CT of the chest with model-based, fully iterative reconstruction: comparison with adaptive statistical iterative reconstruction.

BACKGROUND: The recently developed model-based iterative reconstruction (MBIR) enables significant reduction of image noise and artifacts, compared with adaptive statistical iterative reconstruction (ASIR) and filtered back projection (FBP). The purpose of this study was to evaluate lesion detectability of low-dose chest computed tomography (CT) with MBIR in comparison with ASIR and FBP. METHODS: Chest CT was acquired with 64-slice CT (Discovery CT750HD) with standard-dose (5.7 ± 2.3 mSv) and low-dose (1.6 ± 0.8 mSv) conditions in 55 patients (aged 72 ± 7 years) who were suspected of lung disease on chest radiograms. Low-dose CT images were reconstructed with MBIR, ASIR 50% and FBP, and standard-dose CT images were reconstructed with FBP, using a reconstructed slice thickness of 0.625 mm. Two observers evaluated the image quality of abnormal lung and mediastinal structures on a 5-point scale (Score 5 = excellent and score 1 = non-diagnostic). The objective image noise was also measured as the standard deviation of CT intensity in the descending aorta. RESULTS: The image quality score of enlarged mediastinal lymph nodes on low-dose MBIR CT (4.7 ± 0.5) was significantly improved in comparison with low-dose FBP and ASIR CT (3.0 ± 0.5, p = 0.004; 4.0 ± 0.5, p = 0.02, respectively), and was nearly identical to the score of standard-dose FBP image (4.8 ± 0.4, p = 0.66). Concerning decreased lung attenuation (bulla, emphysema, or cyst), the image quality score on low-dose MBIR CT (4.9 ± 0.2) was slightly better compared to low-dose FBP and ASIR CT (4.5 ± 0.6, p = 0.01; 4.6 ± 0.5, p = 0.01, respectively). There were no significant differences in image quality scores of visualization of consolidation or mass, ground-glass attenuation, or reticular opacity among low- and standard-dose CT series. Image noise with low-dose MBIR CT (11.6 ± 1.0 Hounsfield units (HU)) were significantly lower than with low-dose ASIR (21.1 ± 2.6 HU, p < 0.0005), low-dose FBP CT (30.9 ± 3.9 HU, p < 0.0005), and standard-dose FBP CT (16.6 ± 2.3 HU, p < 0.0005). CONCLUSION: MBIR shows greater potential than ASIR for providing diagnostically acceptable low-dose CT without compromising image quality. With radiation dose reduction of >70%, MBIR can provide equivalent lesion detectability of standard-dose FBP CT.

[Outcome for pulmonary metastases from malignant osteogenic and soft tissue sarcomas].

We reviewed outcome for pulmonary metastases from malignant osteogenic and soft tissue sarcomas. From January 2001 to December 2010, 43 patients with pulmonary metastases from malignant osteogenic and soft tissue sarcomas were treated. Twenty-four were male and 19 were female. Age ranged 12~86 (median 47.3) years. Operations were performed in 12 cases (group O), radiofrequency ablations were performed in 16 cases (group R), and both were performed in 13 cases (group OR). Overall 5-year survival rate was 24.5%. The 5-year survival was 50.2% for patients with a disease-free interval of more than 12 months and 6.1% for those with a disease-free interval of less than 12 months. There was significant difference in cases of bilateral pulmonary metastases between the group O and the other 2 groups. There was significant difference in the numbers of treated lesions between the group OR and the other 2 groups. There was no difference in overall survival among the 3 groups. These results might suggest that the hybrid therapy of operation and radiofrequency ablation improves the prognosis of patients with pulmonary metastases from malignant osteogenic and soft tissue sarcomas.

Assessment of factors influencing FDG uptake in non-small cell lung cancer on PET/CT by investigating histological differences in expression of glucose transporters 1 and 3 and tumour size.

PURPOSE: The objective of this study was to evaluate the major factors influencing on FDG uptake in non-small cell lung cancer (NSCLC) by investigating histological difference in the expression of glucose transporters 1 and 3 (Glut-1 and Glut-3) and tumour size. METHODS: This study enrolled 32 patients including 9 with squamous cell carcinoma (SCC) and 23 with adenocarcinoma (AC). The AC cases comprised 16 AC with mixed subtypes (AC-mixed) and 7 localized AC in situ (localized bronchioloalveolar carcinoma). Partial volume effect corrected maximum standardized uptake values (cSUVmax) and tumour size were obtained using FDG PET/CT. Glut-1 and Glut-3 expression were evaluated using five-point grading scales. RESULTS: Overexpression of Gluts was observed at high rates (88% for Glut-1 and 97% for Glut-3). They were mutually correlated. cSUVmax showed better correlation with size than with Gluts overexpression. AC and SCC showed a high positive expression rate for both Glut-1 and Glut-3, although the degree of overexpression was significantly higher in SCC than AC. In addition, localized AC in situ revealed a considerably higher positive expression rate and similar degrees of overexpression for both Glut-1 and Glut-3 compared with AC-mixed. By contrast, localized AC in situ alone was significantly smaller in both cSUVmax and size than either SCC or AC-mixed. No significant difference was found in cSUVmax or size between SCC and AC-mixed. CONCLUSIONS: The FDG uptake of NSCLC might be dependent on size rather than on overexpression of Glut-1 or Glut-3. Low FDG uptake in localized AC in situ might result from its small size rather than Glut overexpression.

Optimal scan parameters for CT fluoroscopy in lung interventional radiologic procedures: relationship between radiation dose and image quality.

PURPOSE: To evaluate the relationship between radiation doses and lung computed tomographic (CT) fluoroscopic scan parameters and to determine optimal scan parameters for performance of lung interventional radiologic (IR) procedures. MATERIALS AND METHODS: The institutional review board approved this prospective study, which included 32 patients with a single lung tumor; written informed consent was obtained. CT fluoroscopic images were obtained with three tube voltages (80,120,135 kV) and three tube currents (10, 20, 30 mA) in each patient. The signal-to-noise ratios (SNRs) and the contrast-to-noise ratios (CNRs) were measured quantitatively. To evaluate the feasibility of performing lung IR procedures, four readers visually scored the image quality. Acceptable CT fluoroscopic images were determined by using agreement of at least three of the four readers. The weighted CT dose index for each CT scan parameter was measured. A piecewise linear regression equation was obtained from the relationship between radiation doses and visual image scores. RESULTS: Both the SNR and the CNR improved as the radiation dose increased, leading to improvement in the image quality. Acceptable image quality was achieved in 94% (30 of 32) of patients when the radiation dose was 1.18 mGy/sec (120 kV, 10 mA) and in all patients when it was greater than 1.48 mGy/sec (135 kV, 10 mA). The piecewise linear curve showed rapid improvement in image quality until the radiation dose increased to 1.48 mGy/sec (135 kV, 10 mA). When the radiation dose was increased greater than 1.48 mGy/sec, improvement in the image quality became more gradual. CONCLUSION: Results of this study can be used to guide the determination of optimal scan parameters in lung CT fluoroscopy.

Massive hemoptysis from pulmonary artery pseudoaneurysm caused by lung radiofrequency ablation: successful treatment by coil embolization.

A 75-year-old man received lung radiofrequency (RF) ablation to treat lung metastases from hepatocellular carcinoma. Massive hemoptysis occurred 1 week after lung RF ablation. Emergent contrast-enhanced CT and pulmonary arteriography revealed a pulmonary artery pseudoaneurysm, which was embolized with coils. The postembolization course was uneventful. Hemoptysis did not recur for 5 months.

Absolute blood contrast concentration and blood signal saturation on myocardial perfusion MRI: estimation from CT data.

PURPOSE: To determine the optimal contrast injection rate and absolute blood gadolinium concentration for optimal first-pass imaging. MATERIALS AND METHODS: The concentration of contrast medium in left ventricle (LV) was estimated from dynamic computed tomography (CT) by administering iodinated contrast medium of volume (0.2 mL/kg) equivalent to 0.1 mmol/kg of gadolinium injection in 50 subjects. A blood sample study was performed to determine the relationship between blood signal and gadolinium concentration on perfusion MRI. RESULTS: The mean peak gadolinium concentration in LV increased as the injection rate increased from 1 mL/sec (3.7 +/- 1.2 mM), to 4 mL/sec (6.9 +/- 2.7 mM) (P < 0.01). However, no significant improvement was found with an increase in the injection rate from 4 mL/sec to 5 mL/sec (6.8 +/- 1.5 mM, P = 0.86). In a blood sample study the linear relationship between blood signal and gadolinium concentration was maintained in the range of < or =0.67 mM (r = 0.992), which corresponds to a peak blood concentration following a 0.01 mmol/kg gadolinium injection. CONCLUSION: The optimal contrast injection rate for myocardial perfusion magnetic resonance imaging (MRI) appears to be 4 mL/sec. Saturation of arterial input signal is inevitable if the dose of gadolinium contrast medium exceeds 0.01 mmol/kg. These findings are essential for accurate quantification of myocardial blood flow from perfusion MRI.

Increased oxidative stress is associated with decreased circulating levels of adiponectin in Japanese metabolically obese, normal-weight men with normal glucose tolerance.

To investigate the relationship between oxidative stress and circulating levels of adiponectin in Japanese metabolically obese, normal-weight [MONW; BMI<25 and visceral fat area; VFA > or =100 cm2 by abdominal computed tomography (CT) scanning] men with normal glucose tolerance (NGT), we measured the plasma levels of free 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha) and adiponectin in 28 MONW and 23 normal men. The plasma levels of free 8-epi-PGF2alpha were measured using a commercially available enzyme immunoassay (EIA) kit (Cayman Chemical, Ann Arbor, MI). The plasma levels of adiponectin were measured using a radioimmunoassay kit (LINCO Research, St. Charles, MO). Plasma levels of 8-epi-PGF2alpha in MONW subjects (30.4+/-4.0 pg/ml; P<0.01) were significantly increased compared to controls (8.1+/-1.3 pg/ml). The plasma levels of adiponectin were significantly decreased in MONW subjects (8.6+/-0.9 microg/ml; P<0.01) as compared to normal subjects (11.6+/-0.6 microg/ml). The plasma levels of 8-epi-PGF2alpha and adiponectin were significantly correlated in MONW (r=-0.617, P<0.01) and in all (MONW+normal) (r=-0.620, P<0.01) subjects. The plasma levels of 8-epi-PGF2alpha and adiponectin were significantly correlated after adjustment for VFA in MONW subjects (F=11.042, P<0.01). The present study showed that systemic increase in oxidative stress correlates with decreased circulating levels of adiponectin in Japanese MONW men with NGT. Although correlation does not prove causation, this observation suggests that increased oxidative stress may decrease the production of adiponectin in Japanese MONW men with NGT.

Decreased circulating levels of active ghrelin are associated with increased oxidative stress in obese subjects.

OBJECTIVE: To investigate the relationship between active ghrelin and oxidative stress in obese subjects. DESIGN: We measured the plasma levels of free 8-epi-prostaglandin F(2alpha) (8-epi-PGF(2alpha), a reliable and systemic marker of oxidative stress) and the active form of ghrelin in 17 obese and 17 normal subjects. The biologically active forms of ghrelin were measured using a commercially available radio-immunoassay kit and free 8-epi-PGF(2alpha) was measured using an enzyme immunoassay kit. RESULTS: The circulating level of active ghrelin was significantly decreased (20.4 +/- 2.6 vs 40.9 +/- 3.9 fmol/ml, P < 0.01) while that of 8-epi-PGF(2alpha) was significantly increased (61.5 +/- 9.6 vs 17.3 +/- 3.4 pg/ml, P < 0.01) in obese subjects compared with normal subjects. The plasma levels of active ghrelin and 8-epi-PGF(2alpha) were significantly correlated in obese (r = -0.507, P < 0.05) and in all (r = -0.577, P < 0.01) subjects. Multivariate analysis showed that the plasma levels of active ghrelin and 8-epi-PGF(2alpha) were significantly and independently correlated in all subjects (F = 7.888, P < 0.01). CONCLUSIONS: There is an inverse correlation between circulating levels of active ghrelin and oxidative stress in obesity. Low circulating levels of active ghrelin may enhance oxidative stress and the process of atherosclerosis in obese subjects.

Radiological and pathological correlation of lung malignant tumors treated with percutaneous radiofrequency ablation.

Radiological and histological correlation was evaluated in patients with malignant tumors of the lung that underwent radiofrequency ablation (RFA). One of the patients had a primary lung tumor and another patient had three metastatic lung tumors. RFA was performed under computed tomography (CT) fluoroscopic guidance. CT showed ground glass shadows around the tumoral lesions immediately after RFA, but one week later homogenous opacification without tumoral enhancement was noted. Two months after RFA, most lesions showed cystic changes without activity on FDG-PET. Histological evaluation showed massive coagulation necrosis throughout the tumor and some viable cells at the peripheral areas in all lesions. Although RFA is a promising therapeutic approach for malignant lung tumors, some viable cells may persist in peripheral areas of the tumor.

Quantitative insulin sensitivity check index is a useful indicator of insulin resistance in Japanese metabolically obese, normal-weight subjects with normal glucose tolerance.

To clarify whether quantitative insulin sensitivity check index (QUICKI) is useful as an indicator of insulin resistance in Japanese metabolically obese, normal-weight (MONW, body mass index (BMI) <25 and visceral fat area (VFA) > or = 100 cm2 by abdominal computed tomography scanning) subjects with normal glucose tolerance (NGT). Insulin resistance was measured by QUICKI and euglycemic hyperinsulinemic clamp study (clamp IR) in 27 MONW and 27 normal subjects (BMI <25 and visceral fat area <100 cm2). QUICKI (P<0.01) and clamp IR (p<0.01) were significantly decreased in MONW subjects compared with normal subjects. QUICKI was significantly associated with VFA [MONW subjects: r = -0.459, p<0.02; all (MONW and normal) subjects: r = -0.506, p<0.0001] and with the serum levels of triglycerides (MONW subjects: r = -0.386, p<0.05; all subjects: r = -0.505, p<0.001) in MONW and all subjects. There were significant correlations between clamp IR and VFA (MONW subjects: r = -0.562, p<0.01; all subjects: r = -0.575, p<0.0001), fasting serum levels of insulin (MONW subjects: r = -0.673, p<0.001; all subjects: r = -0.619, p<0.0001) or serum levels of triglycerides (MONW subjects: r = -0.485, p<0.02; all subjects: r = -0.565, p<0.0001) in MONW and all subjects. QUICKI was significantly correlated with clamp IR in MONW (r = 0.754, p<0.0001) and in all subjects (r = 0.568, p<0.0001). QUICKI may be an useful method for assessing insulin resistance in Japanese MONW subjects with NGT.

Circulating levels of active ghrelin is associated with abdominal adiposity, hyperinsulinemia and insulin resistance in patients with type 2 diabetes mellitus.

OBJECTIVE: To investigate the relationship between the circulating level of active ghrelin and abdominal adiposity, serum levels of insulin or insulin resistance in patients with type 2 diabetes mellitus. DESIGN: We measured the plasma levels of the active form of ghrelin in 18 obese and 18 nonobese patients with type 2 diabetes mellitus using a radioimmunoassay (RIA) kit. Body fat accumulation was measured by computed tomography (CT) and insulin resistance by the glucose infusion rate (GIR) during an euglycemic hyperinsulinemic clamp study. RESULTS: Plasma levels of ghrelin in obese patients with type 2 diabetes mellitus were significantly decreased compared with nonobese patients. There were significant correlations between the plasma levels of ghrelin and BMI (r=-0.505, P<0.01), visceral (r=-0.444, P<0.01), subcutaneous (r=-0.506, P<0.01) and total (r=-0.534, P<0.01) fat area, serum levels of insulin (r=-0.513, P<0.01) or GIR (r=0.478, P<0.01) in type 2 diabetic patients. The plasma level of ghrelin was significantly associated with serum levels of insulin (F=8.468, P<0.05) or GIR (F=8.522, P<0.05) after adjustment for BMI in patients with type 2 diabetes mellitus. CONCLUSIONS: Decreased plasma levels of active ghrelin are significantly associated with abdominal adiposity, hyperinsulinemia and insulin resistance in type 2 diabetic patients. Hyperinsulinemia associated with insulin resistance may suppress plasma levels of active ghrelin in patients with type 2 diabetes mellitus.