Publication: Aktive kahverengi yağ dokusunun kan lipid profili, karaciğer fonksiyon testleri ve non alkolik yağlı karaciğer hastalığı ile ilişkisi
Abstract
AKTİVE KAHVERENGİ YAĞ DOKUSUNUN KAN LİPİD PROFİLİ, KARACİĞER FONKSİYON TESTLERİ VE NON ALKOLİK YAĞLI KARACİĞER HASTALIĞI İLE İLİŞKİSİ Amaç: Bu çalışmanın amacı malignite şüphesi veya evreleme nedeni ile FDG PET/ BT çekilen olgularda, aktive kahverengi yağ dokusu (AKYD) varlığı ile kan lipid profili, karaciğer fonksiyon testleri (KCFT) ve non alkolik yağlı karaciğer hastalığı (NAYKH) arasındaki ilişkinin araştırılmasıdır. Materyal ve Metod: Malignite tanısı veya malignite şüphesi olan toplam 5907 olguya ait 11820 FDG-PET/ BT çalışması retrospektif ve prospektif olarak incelendi. PET/ BT'de boyunda, mediastende, supraklaviküler ve paravertebral alanlarda adipoz doku içerisinde simetrik olmak üzere geri plan aktivitesinden yüksek miktarda FDG akümülasyonu izlenen olgular AKYD (+) olarak tanımlandı. Çalışmadaki her bir AKYD (+) olgu; elde edilen bölgesel meteorolojik veriler ışığında (C°) ve yaş, cinsiyet ile vücut kitle endeksi (VKİ) göz önünde bulundurularak, ilk evreleme veya tanı amacı ile FDG PET/ BT çekilen 3 KYD (-) olgu ile bire bir eşlendi. Tüm olgular için karaciğer ile dalaktan en az 5 farklı kesitten olmak üzere atenüasyon katsayısı (HU) ölçümleri yapıldı. Karaciğer/ Dalak ortalama HU değeri 1’in altında kalan veya karaciğer ortalama HU değeri 40’ın altında olan olgular anamnezinde alkol kullanılmasının irdelenmesi sonrasında NAYKH olarak belirlendi. Çalışmaya katılan tüm hastaların PET/ BT çekiminden önce kan lipid parametreleri ve karaciğer fonksiyon testlerinin değerlendirilmesi için kan numuneleri alındı. Bulgular: Taranan 5907 olgudan çalışma kriterlerine uyan 25 olgu (9 erkek, 16 kadın) AKYD(+) olarak değerlendirildi. Bu olgular elde edilen bölgesel iv meteorolojik veriler ışığında (C°) ve yaş, cinsiyet ile vücut kitle endeksi (VKİ) göz önünde bulundurularak, ilk evreleme veya tanı amacı ile FDG PET/ BT çekilen 75 KYD (-) olgu ile eşlendi. AKYD (+) olgularda total kolesterol, düşük dansiteli lipoprotein (LDL), alanin aminotransferaz (ALT) ve aspartat transaminaz (AST) seviyeleri KYD (-) kontrol grubuna göre düşük düzeylerde bulunmuştur (p<0.05). Serum trigliserit ve yüksek dansiteli lipoprotein (HDL) değerlerinde ise istatistiksel anlamlı bir fark saptanmamıştır. Ayrıca AKYD(+) olgularda NAYKH görülme sıklığı, AKYD (-) olgulara göre daha az bulunmuştur (p<0,01). Sonuç: Sonuç olarak çalışmamız AKYD varlığının erişkin kan lipid profili ve KCFT üzerine olumlu etkileri olduğunu ve NAYKH görülme sıklığını ise azalttığını göstermiştir. Bu bilgiler ışığında çalışmamız AKYD’nin dislipidemi ile NAYKH’nın önlenmesi ve tedavisinde potansiyel bir hedef olabileceğini düşündürmekle birlikte bu yönde daha kapsamlı çalışmalara ihtiyaç duyulmaktadır. v
ASSOCIATION BETWEEN THE PRESENCE OF ACTİVE BROWN ADİPOSE TISSUE AND BLOOD LIPID PROFILE, LIVER FUNCTION TEST AND NON ALCOHOLIC FATTY LIVER DISEASE IN ADULT HUMANS Aim: The aim of this study is to investigate whether the presence of activated brown adipose tissue (ABAT) in patients undergoing FDG PET-CT examinations for suspected malignancy or staging purposes is related to blood lipid profile, liver function tests and non-alcoholic fatty liver disease (NAFLD). Material and Methods: We analysed 11820 consecutive PET-CT whole-body scans performed on a total of 5907 patients who were referred for suspected malignancies or staging purposes retrospectively and prospectively. ABAT (+) cases were defined as subjects who showed substantial amounts of activated brown adipose tissue symmetrically in neck, mediastinum, supraclavicular and paravertebral regions on PET-CT scans. In the light of regional outdoor temperature (C°) and by taking into consideration of age, gender and body mass index (BMI) each ABAT (+) patient was enrolled one to one with three BAT (-) subjects. The attenuation coefficient (HU) measurements of liver and spleen were performed, at least in five different sections for all cases. A ratio of mean liver attenuation to spleen attenuation less than 1.0 or mean liver HU value below 40 on CT scans in cases without a history of alcohol abuse was considered to indicate NAFLD. Blood samples were taken immediately before PET/ CT to assess patient’s blood lipid profile and liver function tests. vResults: Twenty five out of the 5907 screened individuals fulfilling the criteria for study ( 9 men, 16 women) demonstrated brown fat tissue uptake [ABAT(+) subjects]. Seventy five individuals with the similar age, gender and outdoor temperature at the time of the scan who having no evidence of BAT on PET scans performed for initial staging or diagnostic purposes (BAT- subjects) were enrolled for comparison purposes. After adjustment for potential confounders, ABAT(+) group had lower total cholesterol, low density lipoprotein cholesterol (LDL), alanin aminotranspherase (ALT) and aspartate transaminase (AST) levels (p<0.05). The levels of serum triglyceride and high density lipoprotein (HDL) were not significantly different between ABAT(+) and BAT-negative subjects. In addition, the prevelance of NAFLD in cases with ABAT (+) was lower compared to ABAT (-) (p<0.01). Conclusion: In conclusion, our study showed that the presence of ABAT in adults has positive impact on blood lipid profile, liver function tests and also reduces the prevalence of NAFLD suggesting that active BAT may be a potential target for preventing and treating dyslipidemia and NAFLD.
ASSOCIATION BETWEEN THE PRESENCE OF ACTİVE BROWN ADİPOSE TISSUE AND BLOOD LIPID PROFILE, LIVER FUNCTION TEST AND NON ALCOHOLIC FATTY LIVER DISEASE IN ADULT HUMANS Aim: The aim of this study is to investigate whether the presence of activated brown adipose tissue (ABAT) in patients undergoing FDG PET-CT examinations for suspected malignancy or staging purposes is related to blood lipid profile, liver function tests and non-alcoholic fatty liver disease (NAFLD). Material and Methods: We analysed 11820 consecutive PET-CT whole-body scans performed on a total of 5907 patients who were referred for suspected malignancies or staging purposes retrospectively and prospectively. ABAT (+) cases were defined as subjects who showed substantial amounts of activated brown adipose tissue symmetrically in neck, mediastinum, supraclavicular and paravertebral regions on PET-CT scans. In the light of regional outdoor temperature (C°) and by taking into consideration of age, gender and body mass index (BMI) each ABAT (+) patient was enrolled one to one with three BAT (-) subjects. The attenuation coefficient (HU) measurements of liver and spleen were performed, at least in five different sections for all cases. A ratio of mean liver attenuation to spleen attenuation less than 1.0 or mean liver HU value below 40 on CT scans in cases without a history of alcohol abuse was considered to indicate NAFLD. Blood samples were taken immediately before PET/ CT to assess patient’s blood lipid profile and liver function tests. vResults: Twenty five out of the 5907 screened individuals fulfilling the criteria for study ( 9 men, 16 women) demonstrated brown fat tissue uptake [ABAT(+) subjects]. Seventy five individuals with the similar age, gender and outdoor temperature at the time of the scan who having no evidence of BAT on PET scans performed for initial staging or diagnostic purposes (BAT- subjects) were enrolled for comparison purposes. After adjustment for potential confounders, ABAT(+) group had lower total cholesterol, low density lipoprotein cholesterol (LDL), alanin aminotranspherase (ALT) and aspartate transaminase (AST) levels (p<0.05). The levels of serum triglyceride and high density lipoprotein (HDL) were not significantly different between ABAT(+) and BAT-negative subjects. In addition, the prevelance of NAFLD in cases with ABAT (+) was lower compared to ABAT (-) (p<0.01). Conclusion: In conclusion, our study showed that the presence of ABAT in adults has positive impact on blood lipid profile, liver function tests and also reduces the prevalence of NAFLD suggesting that active BAT may be a potential target for preventing and treating dyslipidemia and NAFLD.