Tag: body mass index

Long COVID: an estrogen-associated autoimmune disease?

Introduction:

Some people who have had severe to a moderate or mild form of COVID-19 disease may suffer from variable and debilitating symptoms for many months after the initial infection. This condition is commonly called “Long COVID”. An exact definition is missing, but symptoms with a duration of more than 2 months are typically considered as Long COVID. The condition is characterized by long-term sequelae and can involve a range of symptoms such as persistent fatigue, headache, shortness of breath, anosmia, muscle weakness, fever, cognitive dysfunction (brain fog), tachycardia, intestinal disorders, and skin manifestations. Long COVID syndrome bears a similarity to the post-infectious syndromes that followed the outbreaks of chikungunya and Ebola.

In general, women appear to be twice as likely to develop Long COVID as men, but only until around age 60, when the risk level becomes similar. In addition to being a woman, older age and a higher body mass index also seem to be risk factors for having Long COVID.

Source: Ortona E, Buonsenso D, Carfi A, Malorni W; Long Covid Kids study group. Long COVID: an estrogen-associated autoimmune disease? Cell Death Discov. 2021 Apr 13;7(1):77. doi: 10.1038/s41420-021-00464-6. PMID: 33850105; PMCID: PMC8042352.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8042352/ (Full text)

A longitudinal study of physical activity and body mass index among persons with unexplained chronic fatigue

Abstract:

OBJECTIVE AND METHODS: A cohort of 100 patients with unexplained chronic fatigue (CF) was assessed longitudinally for 1.5 years to determine if physical activity (kcal expended), exercise capacity (VO(2)max), perceived exertion, and body mass index (BMI) changed over time and were associated with changes in CF-related clinical status.

RESULTS: BMI increased significantly over time but did not predict changes in clinical status. Increasing energy expenditure was associated with increasing vitality and decreasing CF symptom severity over time, and decreasing perceived exertion was associated with increasing physical functioning. However, increasing perceived exertion was also associated with increasing CF symptoms.

CONCLUSIONS: These data do not support models that posit associations between CF and deconditioning.

 

Source: Schmaling KB, Fiedelak JI, Bader J, Buchwald D. A longitudinal study of physical activity and body mass index among persons with unexplained chronic fatigue. J Psychosom Res. 2005 Apr;58(4):375-81. http://www.ncbi.nlm.nih.gov/pubmed/15992573

 

Biochemical and muscle studies in patients with acute onset post-viral fatigue syndrome

Abstract:

AIMS: To investigate in detail various biochemical and pathophysiological indices of muscle pathology in acute onset post-viral fatigue syndrome (PVFS).

METHODS: Twenty three patients with PVFS (of mean duration 4.6 years) were subjected to needle biopsy for histomorphometry and total RNA contents. Plasma analysis included serology and creatine kinase activities. Indices of whole body mass were also measured–namely, whole body potassium content and plasma carnosinase activities.

RESULTS: About 80% of the patients had serology indicative of persistent enteroviral infection as determined by VP1 antigen assay. Only about 10% of that same group of patients had serological indications of current enterovirus infection by IgM assay; a separate subset of 10% showed antibody changes suggestive of reactivation of Epstein-Barr virus. Quantitative morphometric analysis of skeletal muscle fibres indicated that the quadriceps muscle was normal or displayed only minor abnormalities in 22 patients. The Quetelet’s Index (body mass index) and whole-body potassium values (index of lean body mass) were not affected in PVFS. The mean plasma carnosinase and creatinine kinase activities were also generally normal in these patients. The mean muscle RNA composition–mg RNA/mg DNA: was significantly reduced in acute onset PVFS by about 15%. The protein:DNA ratio was not significantly affected.

CONCLUSIONS: Patients with acute onset PVFS, therefore, lose muscle protein synthetic potential, but not muscle bulk. Histopathology is consistent with these observations. These perturbations may contribute to the apparent feature of perceived muscle weakness associated with the persistent viral infection in the muscle themselves.

 

Source: Preedy VR, Smith DG, Salisbury JR, Peters TJ. Biochemical and muscle studies in patients with acute onset post-viral fatigue syndrome. J Clin Pathol. 1993 Aug;46(8):722-6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC501456/