Adiposity in Depression or Depression in Adiposity? The Role of Immune-Inflammatory-Microbial Overlap

Milk kefir drink may not reduce depression in patients with non-alcoholic fatty liver disease: secondary outcome analysis of a randomized, single-blinded, controlled clinical trial

BACKGROUND

Depression is prevalent among individuals with non-alcoholic fatty liver disease (NAFLD) and can cause poor health outcomes. Moreover, a solid bilateral association between NAFLD and depression has been shown, which may alleviate by kefir consumption. Thus, we aimed to investigate the effect of milk kefir drinks on the depression status of individuals with NAFLD.

METHODS

In a secondary outcome analysis of a randomized, single-blinded, controlled clinical trial, 80 adults with grades 1 to 3 of NAFLD were included in an 8-week intervention. Participants were randomly assigned to Diet or Diet + kefir groups to either follow a low-calorie diet or a low-calorie diet along with a 500 cc milk kefir drink daily. The participants' demographic, anthropometric, dietary, and physical data were recorded before and after the study. Depression status was assessed using the Persian format of the second version of the Beck Depression Inventory (BDI-II-Persian) at the baseline and after 8 weeks of intervention.

RESULTS

Overall, 80 participants aged 42.87 ± 10.67 years were included in the analysis. The data on the baseline demographic, dietary, and physical activity of the groups were not significantly different. During the study, participants in Diet + Kefir group had a significantly decreased energy (P = 0.02), carbohydrate (P = 0.4), and fat consumption (P = 0.4). However, during the study, the depression score was not significantly reduced in the Diet group, the Diet + Kefir group showed a significant reduction in depression (P = 0.02). However, between-group analyses for changes in depression were not significant (P = 0.59).

CONCLUSION

Consumption of milk kefir drink for 8 weeks may not reduce depression symptoms in adults with NAFLD.

TRIAL REGISTRATION

The trial was registered at IRCT.ir as IRCT20170916036204N6 (August 2018).

Impact of nonalcoholic fatty liver disease-related metabolic state on depression

Nonalcoholic fatty liver disease (NAFLD), also recently referred as metabolic (dysfunction)-associated fatty liver disease (MAFLD), is characterized by hepatocyte steatosis in the setting of metabolic risk conditions and in the absence of an underlying precursor, for instance alcohol consumption, hepatotropic viruses and hepatotoxic drugs. A possible association between NAFLD and depression has been proposed, owing to intersecting pathophysiological pathways. This narrative review aimed to summarize the current evidence that illustrate the potential pathophysiological and clinical linkage between NAFLD-related metabolic state and depression. Prefrontal cortex lesions are suggested to be a consequence of liver steatosis-associated systematic hyperinflammatory state, a phenomenon also occurring in depression. In addition, depressive symptoms are present in neurotransmitter imbalances. These abnormalities seem to be correlated with NAFLD/MAFLD, in terms of insulin resistance (IR), ammonia and gut dysbiosis' impact on serotonin, dopamine, noradrenaline levels and gamma aminobutyric acid receptors. Furthermore, reduced levels of nesfatin-1 and copine-6-associated BDNF (brain-derived neurotrophic factor) levels have been considered as a probable link between NAFLD and depression. Regarding NAFLD-related gut dysbiosis, it stimulates mediators including lipopolysaccharides, short-chain fatty acids and bile acids, which play significant role in depression. Finally, western diet and IR, which are mainstay components of NAFLD/MAFLD, are, also, substantiated to affect neurotransmitters in hippocampus and produce neurotoxic lipids that contribute to neurologic dysfunction, and thus trigger emotional disturbances, mainly depressive symptoms.

Depressive symptoms and mortality-findings from Helsinki birth cohort study

BACKGROUND

Individuals with depression and depressive symptoms have a higher mortality rate than non-depressed individuals. The increased comorbidity and mortality associated with depression has remained largely unexplained. The underlying pathophysiological differences between depressive subtypes, melancholic and non-melancholic, may provide some explanation to this phenomenon.

METHODS

One thousand nine hundred and ninety five participants (mean age 61 years) from the Helsinki Birth Cohort Study were recruited for this prospective study and followed up for a mean of 14.1 years. Information regarding medical history, lifestyle, and biochemical parameters were obtained. Depressive symptoms were assessed using the Beck Depression Inventory. Standardized mortality ratios were calculated.

RESULTS

Participants were followed up for a total of 28,044 person-years. The melancholic depressive group had an increased adjusted risk of mortality [HR 1.49 (95% CI: 1.02-2.20)] when compared to the non-depressive group. Comparing mortality to the whole population of Finland using standardized mortality ratios (SMR) both the non-melancholic [1.11 (95% CI: 0.85-1.44)] and melancholic depressive [1.26 (95% CI: 0.87-1.81)] groups had higher mortality than the non-depressive group [0.82 (95% CI: 0.73-0.93)].

CONCLUSIONS

Melancholic depressive symptoms are most strongly related to a higher mortality risk.

Non-melancholic depressive symptoms are associated with above average fat mass index in the Helsinki birth cohort study

There is an existing link between two of the most common diseases, obesity and depression. These are both of great public health concern, but little is known about the relationships between the subtypes of these conditions. We hypothesized that non-melancholic depressive symptoms have a stronger relationship with both body composition (lean mass and fat mass) and dysfunctional glucose metabolism than melancholic depression. For this cross-sectional study 1510 participants from the Helsinki Birth Cohort Study had their body composition evaluated as lean mass and fat mass (Lean Mass Index [LMI, kg/m²] + Fat Mass Index [FMI kg/m²] = Body Mass Index). Participants were evaluated for depressive symptoms utilizing the Beck depression inventory, and had laboratory assessments including an oral glucose tolerance test. Higher than average FMI was associated with a higher percentage (mean [%], 95% CI) of participants scoring in the depressive range of the Beck depression inventory (20.2, 17.2–23.2) compared to those with low FMI (16.3, 13.8–18.9; p = 0.048) when adjusted for age, sex, education, and fasting plasma glucose concentration. Higher FMI was associated with a higher likelihood of having depressive symptoms (OR per 1-SD FMI = 1.37, 95% CI 1.13–1.65), whereas higher LMI was associated with a lower likelihood of having depressive symptoms (OR per 1-SD LMI = 0.76, 95% CI 0.64–0.91). Participants with an above average FMI more frequently (mean [%], 95% CI) had non-melancholic depressive symptoms (14.7, 11.8–17.7) as compared to those with low FMI (9.7, 7.6–11.9; p = 0.008) regardless of LMI levels. There was no difference between the body composition groups in the likelihood of having melancholic depressive symptoms. The non-melancholic group had higher (mean [kg/m²], SD) FMI (9.6, 4.1) than either of the other groups (BDI < 10: 7.7, 3.1; melancholic: 7.9, 3.6; p < 0.001), and a higher (mean [mmol/l], SD) 2-h glucose concentration (7.21, 1.65) than the non-depressed group (6.71, 1.70; p = 0.005). As hypothesized, non-melancholic depressive symptoms are most closely related to high fat mass index and dysfunctional glucose metabolism.

Is Fatty Liver Associated With Depression? A Meta-Analysis and Systematic Review on the Prevalence, Risk Factors, and Outcomes of Depression and Non-alcoholic Fatty Liver Disease

Background and Aims: Both non-alcoholic fatty liver disease (NAFLD) and depression have a high global prevalence which is projected to increase further. While studies exploring the association have been done, there are conflicting data. This study aims to assess the prevalence and association between depression and NAFLD.

Methods: Medline and Embase were searched from inception to March 3, 2020. Meta-analysis of proportions using the generalized linear mix model was conducted to analyze the pooled prevalence of depression in NAFLD patients. Risk factors for depression in NAFLD patients were evaluated in conventional pairwise meta-analysis.

Results: Ten studies involving 2,041,752 NAFLD patients were included. Pooled prevalence of depression was 18.21% (CI: 11.12–28.38%) in patients with NAFLD and 40.68% (CI: 25.11–58.37%) in patients with non-alcoholic steatohepatitis (NASH). NAFLD resulted in significantly higher risk of development of depression (OR: 1.29, CI: 1.02–1.64, p = 0.03). NASH patients had a significantly higher risk of depression compared with NAFLD patients (RR: 2.83, CI: 2.41–3.32, p < 0.001). Diabetes, body mass index (BMI), female sex, smoking, and history of pulmonary disease were significant risk factors for depression in NAFLD patients.

Conclusion: This study demonstrated a high prevalence of depression in NAFLD patients and a significant association between both conditions. Furthermore, patients with NASH had a significantly higher risk of depression compared with those with NAFLD. Diabetes, BMI, history of lung disease or smoking, and female gender were significant risk factors. Further studies investigating the pathophysiological mechanism underlying depression and NAFLD are needed.

Probiotics as a Treatment for "Metabolic Depression"? A Rationale for Future Studies

Depression and metabolic diseases often coexist, having several features in common, e.g., chronic low-grade inflammation and intestinal dysbiosis. Different microbiota interventions have been proposed to be used as a treatment for these disorders. In the paper, we review the efficacy of probiotics in depressive disorders, obesity, metabolic syndrome and its liver equivalent based on the published experimental studies, clinical trials and meta-analyses. Probiotics seem to be effective in reducing depressive symptoms when administered in addition to antidepressants. Additionally, probiotics intake may ameliorate some of the clinical components of metabolic diseases. However, standardized methodology regarding probiotics use in clinical trials has not been established yet. In this narrative review, we discuss current knowledge on the recently used methodology with its strengths and limitations and propose criteria that may be implemented to create a new study of the effectiveness of probiotics in depressive disorders comorbid with metabolic abnormalities. We put across our choice on type of study population, probiotics genus, strains, dosages and formulations, intervention period, as well as primary and secondary outcome measures.

The Influence of Probiotic Supplementation on Depressive Symptoms, Inflammation, and Oxidative Stress Parameters and Fecal Microbiota in Patients with Depression Depending on Metabolic Syndrome Comorbidity-PRO-DEMET Randomized Study Protocol

There is a huge need to search for new treatment options and potential biomarkers of therapeutic response to antidepressant treatment. Depression and metabolic syndrome often coexist, while a pathophysiological overlap, including microbiota changes, may play a role. The paper presents a study protocol that aims to assess the effect of probiotic supplementation on symptoms of depression, anxiety and stress, metabolic parameters, inflammatory and oxidative stress markers, as well as fecal microbiota in adult patients with depressive disorders depending on the co-occurrence of metabolic syndrome. The trial will be a four-arm, parallel-group, prospective, randomized, double-blind, controlled design that will include 200 participants and will last 20 weeks (ClinicalTrials.gov identifier: NCT04756544). The probiotic preparation will contain Lactobacillus helveticus Rosell^®-52, Bifidobacterium longum Rosell^®-175. We will assess the level of depression, anxiety and stress, quality of life, blood pressure, body mass index and waist circumference, white blood cells count, serum levels of C-reactive protein, high-density lipoprotein (HDL) cholesterol, triglycerides, fasting glucose, fecal microbiota composition and the level of some fecal microbiota metabolites, as well as serum inflammatory markers and oxidative stress parameters. The proposed trial may establish a safe and easy-to-use adjunctive treatment option in a subpopulation of depressive patients only partially responsive to pharmacologic therapy.