Independent and combined associations of upper and lower limb strength with all-cause mortality in community-based older adults: findings from the Chinese Longitudinal Healthy Longevity Survey

OBJECTIVE

With the acceleration of aging progress, China is projected to have the largest older population globally. This study aimed to examine the association of upper limb strength (ULS) and lower limb strength (LLS) with all-cause mortality based on the Chinese Longitudinal Healthy Longevity Survey (2012-2018).

STUDY DESIGN

This is a prospective cohort study.

METHODS

Participants were 2442 older adults (aged 84.98 ± 11.94 years) recruited from eight longevity areas in China. Limb muscle strength was evaluated using handgrip strength and objective physical examinations. Cox proportional hazards regression was used to analyze the association of limb muscle strength with all-cause mortality. Demographic characteristics, health status, and biological markers were included as confounders.

RESULTS

Over a median follow-up period of 42.2 months, 993 older people died. After adjusting for all covariates, low ULS was associated with higher mortality risk (hazard ratio [HR] = 1.51, 95% confidence interval [CI] = 1.25-1.84), and the association of low LLS with all-cause mortality was only significant in women (HR = 1.36, 95% CI = 1.04-1.79). Participants with combined low ULS and low LLS had the highest risk of mortality than those with normal limb muscle strength (hazard ratio = 2.06, 95% confidence interval = 1.61-2.63). The combined association of ULS and LLS with mortality was robust in subgroup and sensitivity analyses.

CONCLUSION

Low ULS and low LLS were independently and synergistically associated with higher all-cause mortality risk. Considering the high prevalence of limb muscle weakness among Chinese older adults, especially the oldest-old, limb strength could be considered as a potential doable mortality predictor for community health care.

Advances in understanding the relationship between oncostatin M and liver regeneration and liver diseases

Oncostatin M (OSM) is a pleiotropic cytokine belonging to the interleukin (IL)-6 family of cytokines. It is closely related structurally and functionally to leukemia inhibitory factor (LIF). There are two types of functional OSM receptors (OSMR): I and II. The binding of OSM to its receptors activates the JAK-STAT and MAPK signal pathways. OSM not only inhibits the proliferation of tumor cells but also participates in several physiological and pathological processes in a variety of cell types and plays key roles in the pathogenesis of multiple diseases, including regulation of inflammatory responses, stimulation of hematopoiesis, regulation of cholesterol metabolism, and induction of neurotrophic peptides. Recent studies suggest that OSM participates in liver regeneration and is closely related to the occurrence and progression of viral hepatitis, non-alcoholic fatty liver disease, liver fibrosis, and liver cancer. This article reviews recent advances in understanding the relationship between OSM and liver generation and liver diseases.

Advances in the prevention and treatment of fatty liver disease

In recent years, lifestyle changes have resulted in a rising prevalence rate of fatty liver disease (FLD). Even worse, there are some misunderstandings concerning the prevention and treatment of FLD. Therefore, it is necessary to improve our understanding of FLD and explore and summarize effective countermeasures for prevention and treatment of FLD. In this article, we will review the recent advances in research of FLD from five aspects: epidemiology, pathogenesis, relationship with metabolic syndrome, misunderstandings concerning prevention and treatment and countermeasures, and highlight the necessity and urgency for prevention and treatment of FLD.

Emphasis on prevention and treatment of hepatic fibrosis

Hepatic fibrosis is a common pathological basis of chronic liver disease and liver cirrhosis. HBV infection is highly prevalent in China and there is an increasing trend of liver disease caused by HCV and other factors. However, no specific virus-eradicating drugs have been available for liver diseases caused by HBV and HCV. Cytokine-triggered and HSC-triggered waterfall effect does not cease with removal of the original pathogenic factor. Therefore, we should raise the awareness of prevention and treatment of hepatic fibrosis and gradually develop a set of basic countermeasures against hepatic fibrosis and standardize its implementation. This paper highlighted some misunderstandings in current prevention and treatment of hepatic fibrosis, and pointed out the necessity and urgency of prevention and treatment of liver fibrosis.

Effects of Salvia miltiorrhiza bunge injection on the status of lipid peroxidation in liver cirrhosis patients with massive upper gastrointestinal hemorrhage

AIM: To study the changes of lipid peroxidation in liver cirrhosis patients with massive upper gastrointestinal hemorrhage and the effects of Salvia miltiorrhiza bunge (SMB) injection on the changes.

METHODS: Ninety-one liver cirrhosis patients with massive upper gastrointestinal hemorrhage were randomly divided into group A (n = 36) and B (n = 55), treated with SMB injection and traditional method, respectively. The dynamic changes of plasma lipid peroxide (LPO) content and superoxide dismutase (SOD) activity were determined in the patients of both groups.

RESULTS: The plasma content of LPO in group B was obviously increased and reached its peak at the 72^th h (11.0 ± 4.1 nmol/L), significantly higher than that at the 12^th h (7.8 ± 3.3 nmol/L, P < 0.01), but it declined in the 1^th week, and recovered in the 4^th week to some extent. LPO content also reached its peak at 72^th h in group A, with a lower-extent change (9.9 ± 4.6 nmol/L vs 7.8 ± 3.1 nmol/L, P < 0.05) and rapid recovery. The activities of SOD in both groups were decreased and reached their lowest values at the 72^th h (group A: 0.9 ± 0.3 nkat/L vs 1.4±0.2 nkat/L, P < 0.01; group B: 0.87 ± 0.2 nkat/L vs 1.3 ± 0.2 nkat/L, P < 0.01). They also recovered in the 4^th wk with different degrees. The prognosis of patients in group A was superior to that in group B, which was correlated with Child-Pugh classification (P<0.05).

CONCLUSION: SMB injection can enhance the antioxidant capability in vivo and improve the prognosis of liver cirrhosis patients with massive upper gastrointestinal hemorrhage.

Effects of interferon-alpha on expression of hepatic stellate cell and transforming growth factor-β1 and α-smooth muscle actin in rats with hepatic fibrosis

AIM: To investigate the effect of interferon-α (IFN-α) on preventing or reversing hepatic fibrosis in rat experimental model induced by CCl₄.

METHODS: One hundred and ten Sprague-Dawley rats were divided into five groups: group A (normal controls, n = 18), group B (fibrotic model controls, n = 22), group C (IFN-α prevention, n = 22) initially treated with intra-muscular injection of IFN-α in saline daily at the doses of 1×10⁵ U for 6 wk, group D (IFN-α treatment, n = 24) treated with intra-muscular injection of IFN-α in saline daily at the doses of 1×10⁵ U for 6 wk after the first 6 wk, group E (0.9% sodium chloride treatment control, n = 24) treated with intra-muscular injection of 0.01 mL/kg daily for 6 wk after the first 6 wk. At the end of the experiment, all rats of each group were killed. Samples of the liver obtained by biopsy were subjected to histological, immunohistochemical and electron microscopic studies for the expressions of transforming growth factor-β1 (TGF- β1) and α-smooth muscle actin (α-SMA).

RESULTS: The expressions of TGF-β1, the number of activated hepatic stellate cells and α-SMA in hepatic tissue of group C were significantly less than those of group B (P<0.01). The degree of fibrosis score in group B was also significantly less than that of group C under light microscope (P<0.01).

CONCLUSION: IFN-α can inhibit the production of TGF-β1, decrease HSC activation and stimulate its apoptosis.

Effects of selenium on peripheral blood mononuclear cell membrane fluidity, interleukin-2 production and interleukin-2 receptor expression in patients with chronic hepatitis

AIM: To study the effect of selenium on peripheral blood mononuclear cell (PBMC) membrane fluidity and immune function in patients with chronic hepatitis.

METHODS: PBMCs were pretreated with selenium (1.156 × 10^-7 mol/L) for 6 h in vitro or extracted directly from patients after administration of selenium-yeast continuously for 8-12 wk (200 μg/d), and then exposed to Con-A for 48 h. The membrane fluidity, interleukin-2 (IL-2) production and interleukin-2 receptor (IL-2R) expression in PBMCs and malondialdehyde (MDA) concentration in medium and lipid peroxide (LPO) in plasma were determined.

RESULTS: The PBMC membrane fluidity, IL-2 production and IL-2R expression in patients with chronic hepatitis were significantly lower than those in healthy blood donators (particle adhesive degree R, 0.17 ± 0.01 vs 0.14 ± 0.01, P < 0.01; IL-2, 40.26 ± 9.55 vs 72.96 ± 11.36, P < 0.01; IL-2R, 31.05 ± 5.09 vs 60.58 ± 10.56, P < 0.01), and the MDA concentration in medium in patients with chronic hepatitis was significantly higher than that in healthy blood donators (1.44 ± 0.08 vs 0.93 ± 0.08, P < 0.01). Both in vitro and in vivo administration of selenium could reverse the above parameters.

CONCLUSION: Supplement of selenium can suppress lipid peroxidation, and improve PBMC membrane fluidity and immune function in patients with chronic hepatitis.

Effects of estradiol on liver estrogen receptor-α and its mRNA expression in hepatic fibrosis in rats

AIM: Estradiol treatment regulates estrogen receptor (ER) level in normal rat liver. However, little information is available concerning the role of estrogen in regulating liver ER in hepatic fibrosis in rats. The present study was conducted to determine whether estradiol treatment in CCl₄-induced liver fibrosis of female and ovariectomized rats altered liver ERα and its mRNA expression, and to investigate the possible mechanisms.

METHODS: Seventy female rats were divided into seven groups with ten rats in each. The ovariectomy groups were initiated with ovariectomies and the sham operation groups were initiated with just sham operations. The CCl₄ toxic fibrosis groups received 400 mL/L CCl₄ subcutaneously at a dose of 2 mL/kg twice weekly. Estrogen groups were treated subcutaneously with estradiol 1 mg/kg, the normal control group and an ovariectomy group received injection of peanut oil vehicle twice weekly. At the end of 8 weeks, all the rats were killed to detect their serum and hepatic indicators, their hepatic collagen content, and liver ER and ER mRNA expression.

RESULTS: Estradiol treatment in both ovariectomy and sham ovariectomy groups reduced liver levels of ALT (from 658 ± 220 nkat/L to 311 ± 146 nkat/L and 540 ± 252 nkat/L to 314 ± 163 nkat/L, P < 0.05) and AST (from 697 ± 240 nkat/L to 321 ± 121 nkat/L and 631 ± 268 nkat/L to 302 ± 153 nkat/L, P < 0.05), increased serum nitric oxide (NO) level (from 53.7 ± 17.1 μmol/L to 93.3 ± 24.2 μmol/L and 55.3 ± 23.1 μmol/L to 87.5 ± 23.6 μmol/L, P < 0.05) and hepatic nitric oxide synthase (NOS) activity (from 1.73 ± 0.71 KU/g to 2.49 ± 1.20 KU/g and 1.65 ± 0.46 KU/g to 2.68 ± 1.17 KU/g, P < 0.05), diminished the accumulation of hepatic collagen, decreased centrolobular necrotic areas as well as the inflammatory reaction in rats subjected to CCl₄. The positive signal of ER and ER mRNA distributed in parenchymal and non-parenchymal hepatic cells, especially near the hepatic centrolobular and periportal areas. Ovariectomy decreased ER level (from 10.2 ± 3.2 to 4.3 ± 1.3) and ER mRNA expression (from 12.8 ± 2.1 to 10.9 ± 1.3) significantly (P < 0.05). Hepatic ER and ER mRNA concentrations were elevated after treatment with estradiol in both ovariectomy (15.8 ± 2.4, 20.8 ± 3.1) and sham ovariectomy (18.7 ± 3.8, 23.1 ± 3.7) fibrotic groups (P < 0.05).

CONCLUSION: The increase in hepatic ER and mRNA expression may be part of the molecular mechanisms underlying the suppressive effect of estradiol on liver fibrosis induced by CCl₄ administration.

Effects of estradiol on type I, III collagens and TGF β1 in hepatic fibrosis in rats

AIM

To study the effects of estradiol on the production of collagen I, III and transforming growth factor β₁ (TGF β₁) in experimental fibrosis in rats induced by carbon tetrachloride (CCL4), and to investigate the suppressive effects of estrogen on liver fibrosis.

METHODS

Rats were randomly allocated into a normal control group, a model control group, a therapy control group and an estradiol group. Liver fibrosis was induced by CCL₄ administration. The estradiol group, apart from the administration of CCL₄, was treated subcutaneously with estradiol (benzoic estradiol) 1 mg/kg twice weekly. At the end of week 8, all the rats were sacrificed. Liver inflammation and collagen deposition were observed with HE and Masson's collagen stains, analyzed with scoring and staging systems. Type I, III collagens and TGF β₁ were observed with immunohistochemical method.

RESULTS

CCL₄ group had the typical liver fibrosis compared with normal control group. The fibrous septa were formed in CCL₄ group rats, and collagens were accumulated and deposited in the sinusoids and liver lobules. The expression of type I , III collagens (0.58±0.26 vs 6.34±2.24, 1.07±0.49 vs 5.28±1.28, P<0.001) and TGF β₁ was significantly increased. Estradiol significantly attenuated collagen accumulation (P<0.05) in the fibrotic livers, and decreased type I , III collagens (2.47±0.76 vs 6.34±2.24, 3.02±1.20 vs 5.28±1.28, P<0.05) and TGF β₁ expression in the liver.

CONCLUSION

Estradiol treatment reduces the synthesis of hepatic type I , III collagens and TGF β₁ in the fibrotic liver induced by CCL₄ administration, and attenuates hepatic fibrosis.

Correlation between expression of cyclooxygenase-2 and angiogenesis in human gastric adenocarcinoma

AIM: To evaluate the expression of cyclooxygenase (COX-2) and the relationship with tumor angiogenesis and advancement in gastric adenocarcinoma.

METHODS: Immunohistochemical stain was used for detecting the expression of COX-2 in 45 resected specimens of gastric adenocarcinoma; the monoclonal antibody against CD34 was used for displaying vascular endothelial cells, and microvascular density (MVD) was detected by counting of CD34-positive vascular endothelial cells. Paracancerous tissues were examined as control.

RESULTS: Immunohistological staining with COX-2-specific polyclonal antibody showed cytoplasmic staining in the cancer cells, some atypical hyperplasia and intestinal metaplasia, as well as angiogenic vasculature present within the tumors and prexisting vasculature adjacent to cancer lesions. The rate of expression of COX-2 and MVD index in gastric cancers were significantly increased, compared with those in the paracancerous tissues (77.78 vs 33.33%, 58.13 ± 19.99 vs 24.02 ± 10.28, P < 0.01, P < 0.05, respectively). In 36 gastric carcinoma specimens with lymph node metastasis, the rate of COX-2 expression and MVD were higher than those in the specimens without metostasis (86.11 vs 44.44%, 58.60 ± 18.24 vs 43.54 ± 15.05, P < 0.05, P < 0.05, respectively). The rate of COX-2 expression and MVD in the specimens with invasive serosa were significantly higher than those in the specimens without invasion to serosa (87.88 vs 50.0%, 57.01 ± 18.79 vs 42.35 ± 14.65, P < 0.05, P < 0.05). Moreover, MVD in COX-2-positive specimens was higher than that in COX-2-negative specimens (61.29 ± 14.31 vs 45.38 ± 12.42, P < 0.05). COX-2 expression was positively correlated with MVD (r = 0.63, P < 0.05).

CONCLUSION: COX-2 expression might correlate with the occurance and advancement of gastric carcinoma and is involved in tumor angiogenesis in gastric carcinoma. It is likely that COX-2 by inducing angiogenesis can be one of mechanisms which promotes invasion and metastasis of gastric carcinoma. It may become a new therapeutic target for anti-angiogenesis.

Estrogen reduces CCL4- induced liver fibrosis in rats

AIM: Chronic liver diseases, such as fibrosis or cirrhosis, are more common in men than in women. This gender difference may be related to the effects of sex hormones on the liver. The aim of the present work was to investigate the effects of estrogen on CCL₄-induced fibrosis of the liver in rats.

METHODS: Liver fibrosis was induced in male, female and ovariectomized rats by CCL₄ administration. All the groups were treated with estradiol (1 mg/kg) twice weekly. And tamoxifen was given to male fibrosis model. At the end of 8 wk, all the rats were killed to study serum indicators and the livers.

RESULTS: Estradiol treatment reduced aspartate aminotransferase (AST), alanine aminotransferase (ALT), hyaluronic acid (HA) and type IV collagen (CIV) in sera, suppressed hepatic collagen content, decreased the areas of hepatic stellate cells (HSC) positive for α-smooth muscle actin (α-SMA), and lowered the synthesis of hepatic type I collagen significantly in both sexes and ovariectomy fibrotic rats induced by CCL₄ administration. Whereas, tamoxifen had the opposite effect. The fibrotic response of the female liver to CCL₄ treatment was significantly weaker than that of male liver.

CONCLUSION: Estradiol reduces CCL₄-induced hepatic fibrosis in rats. The antifibrogenic role of estrogen in the liver may be one reason for the sex associated differences in the progression from hepatic fibrosis to cirrhosis.

Non-specific response of serum growth hormone to thyrotropin-releasing hormone in diabetics

It is well known that growth hormone (GE) secretion and regulation in diabetics are abnormal. In order to evaluate the response of GH to nonphysiological stimuli in diabetics, a thyrotropin-releasing hormone (TRH) test (500 micrograms by IV bolus injection) was carried out in 12 patients with insulin-dependent diabetes (IDD, 6 males and 6 females). 11 noninsulin-dependent diabetes (NIDD, 5 males and 6 females), and 10 normal controls (6 males and 4 females). The results showed that the basal serum GH levels in diabetics were higher than that in normal controls and it was even higher in IDD than in NIDD. Following the TRH stimulus, the mean peak level of GH in IDD was the highest among the three groups, the differences being statistically significant (F = 9.323, P less than 0.01). It was concluded that a nonspecific response to TRH of GH did occur in IDD, and the peak values were even higher in female than in male subjects. A negative correlation existed between the GH peak values and the age of the patients as well as in the controls. This supported the view that GH responsiveness to TRH has a tendency of progressive decline with age. However, no significant correlation was found between the peak value of GH and the blood glucose level or the microangiopathic complications. The mechanism of TRH stimulation on GH release in diabetics is discussed.