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Peter Christopher Konturek

Publications and source records attributed to Peter Christopher Konturek.

6 recordsLinked to original sources
PubMed2005

Insulin resistance and other metabolic aspects of the obstructive sleep apnea syndrome.

Obstructive sleep apnea syndrome (OSAS) is usually associated with conditions known to increase insulin resistance and cardiovascular risk, such as hypertension, obesity, and diabetes. Thus, investigating whether obstructive sleep apnea itself is an independent risk factor for increased insulin resistance and whether continuous positive airway pressure treatment (CPAP) might improve insulin sensitivity brings up considerable methodological problems. Even if insulin sensitivity improves, it is hard to distinguish between an effect of CPAP treatment, e.g. in the reduction of nocturnal sympathetic activity caused by the sleep disturbance, and concomitant factors, such as weight loss. Two recent investigations were able to prove that OSAS is an independent risk factor for insulin resistance: one study in a statistical approach, the other by demonstrating a significant improvement of insulin sensitivity already two days after onset of CPAP therapy, thus clearly ruling out such confounding factors as changes in lifestyle or weight loss. However, it is still not clear if this improvement in insulin sensitivity is accompanied by an improvement in the usually elevated cardiovascular risk of patients with OSAS. Since a decrease in elevated markers of subclinical inflammation--nowadays regarded as the main culprit of cardiovascular complications and atherosclerosis--such as Interleukin-6 and C-reactive protein has been reported during CPAP therapy, and since an improvement in left ventricular function and a decrease in blood pressure were also reported under CPAP treatment, there are several good reasons to assume an improvement in metabolical function in OSAS patients due to CPAP treatment.

Continuous Positive Airway Pressure↗
PubMed2004

Resistin levels in patients with obstructive sleep apnoea syndrome--the link to subclinical inflammation?

BACKGROUND: The role of resistin, a "new" white adipose tissue hormone, still needs to be established. Its linkage to insulin sensitivity and body mass was controversial in previous studies. MATERIAL/METHODS: Twenty obese patients (BMI: 32.1+/-6.9 kg/m2 ) with obstructive sleep apnoea syndrome (OSAS) (Apnoea-Hypopnoea Index: 48.6+/-19.1, underwent measurements of resistin, interleukin-6 (IL-6), intracellular adhesion molecule-1 (ICAM-1), CRP and the insulin sensitivity index (ISI) by hyperinsulinaemic euglycaemic clamp before, 2 days and 2 months after onset of CPAP treatment. RESULTS: Resistin remained unchanged during CPAP-therapy and was negatively correlated to ISI (r=-0.359; p=0.006), the latter was significantly improved by CPAP (p<0.001). In a correlation matrix, IL-6 and ICAM-1 were significantly (p=0.001) correlated to resistin (p=0.614 and 0.427). Changes of inflammatory markers under CPAP treatment were related to AHI, as well as resistin changes. CONCLUSIONS: In agreement with previous investigations, we could only demonstrate a weak linkage between ISI and resistin. However, at least in obese patients with OSAS, there is a close relation to subclinical inflammation (IL-6) and endothelial activation (ICAM-1).

Body Mass Index↗
PubMed2003

Launois-Bensaude syndrome in a female with type 2 diabetes.

BACKGROUND: The Launois-Bensaude syndrome (LBS) is a rare disease characterized by an accumulation of multiple lipomata with a preponderance at the thorax, abdomen, upper arms and the thighs. Frequently, the condition is associated with past or present alcohol abuse with no clear temporal coincidence between the onset and termination of lipomata growth and onset or termination of alcohol consumption. Due to the massive accumulation of adipose tissue, the patients frequently have features of the metabolic syndrome as hypertension, impaired fasting glucose or diabetes mellitus, hyperuricemia or hyperlipidemia. CASE REPORT: A 79-yr-old female observed an increase of fat mass especially at the upper arms, the thighs and the thorax in combination with a weight gain of 19 kg within 2 years without any changes in the nutrition habits. The unique features confirmed the diagnosis of LBS. Interestingly, she had diabetes mellitus, hypertension and hyperlipidemia before the manifestation of LBS and without any history of heavy alcohol consumption. Furthermore, the condition predominantly affects males. In her very case, treatment with sultanol, as successfully performed in some cases, could not be recommended due to her cardiac insufficiency. A surgical approach is of limited value due to the frequent relapses of the lipomata. CONCLUSIONS: Establishing the diagnosis of LBS is an important step for patients confronted with an inexplicable physical disfigurement that is not related to excessive nutrition. The disease is often not diagnosed because of its rareness, but its features are unique and easily to be distinguished from 'simple' truncal obesity.

Aged↗
PubMed2002

Cat-scratch disease in an immunocompromised host.

BACKGROUND: The main causative agents of cat-scratch disease are Bartonella henselae, tiny, gram-negative bacilli. The disease usually has a benign course with the development of a papule at the inoculation site, followed by regional lymphadenopathy. In most cases, complete resolution occurs, but in immunocompromised hosts, the course of the disease can be aggravated. CASE REPORT: A patient received methotrexate and corticosteroids for 3 months due to rheumatoid arthritis. He developed fever, exanthema and leukopenia under methotrexate therapy. Dark red indurations with central ulcerations at his right thigh revealed a further problem apart from the methotrexate-induced leucopenia and immunosuppression. The ulcerations were the remainders of recurrent scratches from the patient's cat. The patient's antibody titers against Bartonella henselae remained low and inguinal lymph node swelling was only for a short time to be observed, this reaction obviously weakened as a result of the immunosuppression. However, the typical course, the exclusion of other reasons for the exanthema and the rapid improvement of the patient's condition after antibiotic treatment ascertained the diagnosis. CONCLUSIONS: In immunocompromised hosts, diseases with a typically benign course can become severe and life-threatening illnesses. Ownership of pets should be taken into consideration before onset of an immunosuppressive therapy.

Aged↗
PubMedDate not supplied

The effect of continuous positive airway pressure treatment on insulin sensitivity in patients with obstructive sleep apnoea syndrome and type 2 diabetes.

BACKGROUND: The obstructive sleep apnoea syndrome (OSA) is a frequent condition, as well as type 2 diabetes mellitus. Both diseases are characterized by insulin resistance. OBJECTIVES: The aim of this study was to establish whether OSA is an independent risk factor for increased insulin resistance in diabetics. For this purpose, we tested the hypothesis that the insulin sensitivity in patients with type 2 diabetes and OSA can be improved by 2 days or 3 months of continuous positive airway pressure (CPAP) treatment. METHODS: In 9 obese patients with type 2 diabetes and OSA [apnoea/hypopnoea index 43.1 +/- 21.3; body mass index (BMI) 37.3 +/- 5.6 kg/m2] and good glycaemic control on oral antidiabetics or on diet alone (HbA1c 6.4 +/- 0.7%), the insulin sensitivity index (ISI) was established by euglycaemic hyperinsulinaemic clamp tests at baseline, after 2 days and after 3 months of effective CPAP treatment. RESULTS: ISI was unchanged after 2 days of CPAP treatment, but was significantly improved after 3 months (4.38 +/- 2.94 vs. 2.74 +/- 2.25 at baseline; p = 0.021), without any significant changes in BMI. Glycaemic control was unaffected after 3 months (HbA1c 6.3 +/- 0.6%; not significant). Fasting leptin levels showed no significant changes. CONCLUSIONS: These results indicate that OSA itself is an independent risk factor for insulin resistance. This effect may be explained by the elevated sympathetic activity in OSA.

Continuous Positive Airway Pressure↗