Resting State Functional Connectivity Biomarkers of Treatment Response in Mood Disorders: A Review

There are currently no validated treatment biomarkers in psychiatry. Resting State Functional Connectivity (RSFC) is a popular method for investigating the neural correlates of mood disorders, but the breadth of the field makes it difficult to assess progress toward treatment response biomarkers. In this review, we followed general PRISMA guidelines to evaluate the evidence base for mood disorder treatment biomarkers across diagnoses, brain network models, and treatment modalities. We hypothesized that no treatment biomarker would be validated across these domains or with independent datasets. Results are organized, interpreted, and discussed in the context of four popular analytic techniques: (1) reference region (seed-based) analysis, (2) independent component analysis, (3) graph theory analysis, and (4) other methods. Cortico-limbic connectivity is implicated across studies, but there is no single biomarker that spans analyses or that has been replicated in multiple independent datasets. We discuss RSFC limitations and future directions in biomarker development.

Left Dorsolateral Prefrontal Cortex Glx/tCr Predicts Efficacy of High Frequency 4- to 6-Week rTMS Treatment and Is Associated With Symptom Improvement in Adults With Major Depressive Disorder: Findings From a Pilot Study

About 20-40% of estimated 121 million patients with major depressive disorder (MDD) are not adequately responsive to medication treatment. Repetitive transcranial magnetic stimulation (rTMS), a non-invasive, non-convulsive neuromodulation/neurostimulation method, has gained popularity in treatment of MDD. Because of the high cost involved in rTMS therapy, ability to predict the therapy effectiveness is both clinically and cost wise significant. This study seeks an imaging biomarker to predict efficacy of rTMS treatment using a standard high frequency 10-Hz 4- to 6-week protocol in adult population. Given the significance of excitatory and inhibitory neurotransmitters glutamate (Glu) and gamma aminobutyric acid (GABA) in the pathophysiology of MDD, and the involvement of the site of rTMS application, left dorsolateral prefrontal cortex (lDLPFC), in MDD, we explored lDLPFC Glx (Glu + glutamine) and GABA levels, measured by single voxel magnetic resonance spectroscopy (MRS) with total creatine (tCr; sum of creatine and phosphocreatine) as reference, as possible biomarkers of rTMS response prediction. Mescher-Garwood point-resolved spectroscopy (MEGA-PRESS) MRS data from 7 patients (40-74 y) were used in the study; 6 of these patients were scanned before and after 6 weeks of rTMS therapy. Findings from this study show inverse correlation between pretreatment lDLPFC Glx/tCr and (i) posttreatment depression score and (ii) change in depression score, suggesting higher Glx/tCr as a predictor of treatment efficacy. In addition association was observed between changes in depression scores and changes in Glx/tCr ratio. The preliminary findings did not show any such association between GABA/tCr and depression score.

Probability of coronary disease and clinical outcomes in patients with type 2 myocardial infarction

Background

Type 2 myocardial infarction is common in clinical practice. However, despite these patients having a similar rate of major adverse cardiovascular events as those with atherothrombotic type 1 myocardial infarction, there is currently no consensus on how these patients should be evaluated or managed. Whether risk assessment for coronary artery disease can identify patients at increased risk of death is unclear.

Methods

The High-STEACS trial was a stepped wedge cluster randomised controlled trial in ten hospitals across Scotland, including 48,282 consecutive patients with suspected acute coronary syndrome. The index diagnosis was adjudicated in all patients and the likelihood of underlying coronary artery disease recorded as either low-probability, high-probability, or known based on the clinical history, risk factors and comorbidities. The adjudicators were blinded to the primary and secondary outcomes including all-cause mortality at one year.

Results

High-sensitivity cardiac troponin I concentrations were above the sex-specific 99th centile in 22% (10,360/48,282) of patients. The adjudicated diagnosis was type 1 and type 2 myocardial infarction in 55% (4,981/9,115) and 12% (1,121/9,115), respectively. Compared to patients with type 1 myocardial infarction, those with type 2 myocardial infarction were older and more likely to be women. In patients with type 2 myocardial infarction, 20% were low-probability, 55% were high-probability and 25% had known coronary artery disease. All-cause mortality was highest in patients with known or suspected coronary artery disease (22.5% and 23.3%, respectively). Those with a low-probability of coronary artery disease had the lowest event rate (8.8%), even compared to those with type 1 myocardial infarction (Figure).

Discussion

A simple clinical assessment of whether patients have a low- or high-probability of coronary artery disease is associated with future risk of death in patients with type 2 myocardial infarction. Whether incorporating this assessment into clinical practice to guide secondary prevention could improve outcomes requires prospective evaluation.

Figure 1

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): British Heart Foundation

The mechanism of supply-demand imbalance and clinical outcomes in patients with type 2 myocardial infarction

Background

Type 2 myocardial infarction is common and associated with substantial risk of adverse clinical outcomes, worse than type 1 myocardial infarction, with as few as 30% of patients still alive at five years. However, this broad diagnostic term encompasses multiple mechanisms of supply-demand imbalance, which may be associated with different risks of adverse outcomes.

Purpose

We aimed to assess the prevalence and clinical outcomes of different mechanisms of supply-demand imbalance related to survival in the High-STEACS (High-Sensitivity Troponin in the Evaluation of patients with Acute Coronary Syndrome) randomised controlled trial.

Methods

The High-STEACS trial was a stepped wedge cluster randomised controlled trial in ten hospitals across Scotland, including 48,282 consecutive patients with suspected acute coronary syndrome. The diagnosis was adjudicated according to the Fourth Universal Definition of Myocardial Infarction. In patients with type 2 myocardial infarction, we prospectively adjudicated the cause for supply demand imbalance. Linkage of electronic healthcare records was used to track investigation, treatments and clinical outcomes. We used the Kaplan-Meier method, the log rank test and cox regression models adjusted for age, sex, renal function and co-morbidities to evaluate the risk of future all-cause mortality between categories.

Results

We identified 1,121 patients with type 2 myocardial infarction (age 74- ± 14, 55% female). At one year, death from any cause occurred in 23% (258/1,121) of patients. The most common reason for supply-demand imbalance was tachyarrhythmia in 55% (616/1,121), followed by hypoxaemia in 20% (219/1,121) of patients. Tachyarrhythmia was associated with reduced future risk of all-cause mortality (adjusted HR 0.69, 95% CI 0.43–1.09), similar to those with type 1 myocardial infarction. Comparatively, patients with hypoxaemia appeared at highest risk (adjusted HR 1.75, 95% CI 1.09–2.80).

Conclusion

The mechanism of myocardial oxygen supply-demand imbalance is associated with future prognosis, and should be considered when risk stratifying patients with type 2 myocardial infarction.

Supply-demand imbalance survival

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): British Heart Foundation

Validation of a machine learned model to predict the diagnosis of myocardial infarction

Introduction

The myocardial-ischemic-injury-index (MI3) is a promising machine learned algorithm that predicts the likelihood of myocardial infarction in patients with suspected acute coronary syndrome. Whether this algorithm performs well in unselected patients or predicts recurrent events is unknown.

Methods

In an observational analysis from a multi-centre randomised trial, we included all patients with suspected acute coronary syndrome and serial high-sensitivity cardiac troponin I measurements without ST-segment elevation myocardial infarction. Using gradient boosting, MI3 incorporates age, sex, and two troponin measurements to compute a value (0–100) reflecting an individual's likelihood of myocardial infarction, and estimates the negative predictive value (NPV) and positive predictive value (PPV). Model performance for an index diagnosis of myocardial infarction, and for subsequent myocardial infarction or cardiovascular death at one year was determined using previously defined low- and high-probability thresholds (1.6 and 49.7, respectively).

Results

In total 20,761 of 48,282 (43%) patients (64±16 years, 46% women) were eligible of whom 3,278 (15.8%) had myocardial infarction. MI3 was well discriminated with an area under the receiver-operating-characteristic curve of 0.949 (95% confidence interval 0.946–0.952) identifying 12,983 (62.5%) patients as low-probability (sensitivity 99.3% [99.0–99.6%], NPV 99.8% [99.8–99.9%]), and 2,961 (14.3%) as high-probability (specificity 95.0% [94.7–95.3%], PPV 70.4% [69–71.9%]). At one year, subsequent myocardial infarction or cardiovascular death occurred more often in high-probability compared to low-probability patients (17.6% [520/2,961] versus 1.5% [197/12,983], P<0.001).

Conclusions

In unselected consecutive patients with suspected acute coronary syndrome, the MI3 algorithm accurately estimates the likelihood of myocardial infarction and predicts probability of subsequent adverse cardiovascular events.

Performance of MI3 at example thresholds

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Medical Research Council

The association between lithium use and neurocognitive performance in patients with bipolar disorder

Lithium remains the gold standard for the treatment of bipolar disorder (BD); however, its use has declined over the years mainly due to the side effects and the subjective experience of cognitive numbness reported by patients. In the present study, we aim to methodically test the effects of lithium on neurocognitive functioning in the largest single cohort (n = 262) of BD patients reported to date by harnessing the power of a multi-site, ongoing clinical trial of lithium monotherapy. At the cross-sectional level, multivariate analysis of covariance (MANCOVA) was conducted to examine potential group differences across neurocognitive tests [California Verbal Learning Test (CVLT trials 1-5,CVLT delayed recall), Wechsler Digit Symbol, Trail-making Test parts A and B (TMT-A; TMT-B), and a global cognition index]. At the longitudinal level, on a subset of patients (n = 88) who achieved mood stabilization with lithium monotherapy, we explored the effect of lithium treatment across time on neurocognitive functioning. There were no differences at baseline between BD patients that were taking lithium compared with those that were not. At follow-up a significant neurocognitive improvement in the global cognitive index score [F = 31.69; p < 0.001], CVLT trials 1-5 [F = 29.81; p < 0.001], CVLT delayed recall [F = 15.27; p < 0.001], and TMT-B [F = 6.64, p = 0.012] was detected. The cross-sectional and longitudinal (on a subset of 88 patients) investigations suggest that lithium may be beneficial to neurocognitive functioning in patients with BD and that at the very least it does not seem to significantly impair cognition when used therapeutically.

Role of structures in the masticator space in selecting patients with resectable T4b oral cancer: findings from a survival analysis

Oral squamous cell cancers involving the masticatory space are staged as unresectable cancers and their treatment is difficult. Curative treatment with extensive surgery followed by adjuvant therapy is one of the treatment options. In this retrospective study, the survival of 123 patients (93 with T4a cancers, 30 with T4b cancers), treated during the period August 2009 to August 2015, was evaluated. The majority had bucco-alveolar cancers (62.6%), were male (61.8%), and were tobacco users (76.4%). The select group of T4b oral cancer patients were treated with surgery, which included infratemporal fossa clearance in all 30 patients, followed by adjuvant therapy. The masseter was the most commonly involved masticatory muscle, and 24 patients had fewer than three involved structures. Free margins were obtained in 90.2% of cases; 41.5% of cases were node-positive. One hundred and four patients (84.6%) completed adjuvant treatment. The median follow-up was 42 months. For node-negative patients with T4a and T4b cancers, the 5-year overall survival was 59% and 50.2%, respectively (P= 0.62), and 5-year disease-free survival was 64.6% and 53.5%, respectively (P= 0.01). In conclusion, the select group of patients with T4b oral cancers and less than three masticatory space structures involved had comparable outcomes to those with T4a cancers after treatment with surgery and adjuvant radiotherapy.

Sustainable Process for the Extraction of Potassium from Feldspar Using Eggshell Powder

To recover potassium from feldspar, a biowaste, i.e., eggshell, was used. The chief composition of eggshells is calcite. As it is a rich source of Ca, hence it is used with HCl to produce calcium chloride. Feldspar is an aluminosilicate mineral that bears potassium in the interstitial sites. To unlock the potassium from the interstitial sites, it was roasted with calcium chloride prepared by mixing eggshell and hydrochloric acid. At the roasting temperature, CaCl₂ melts and penetrates into the aluminosilicate matrix to replace K with Ca. Potassium ion released from the silicate matrix combines with chloride ions to form potassium chloride, which solubilized in water during the leaching process of the roasted feldspar. For elucidation of the mechanism of the roasting process, the shrinking core model was applied to the roast-leach data, and diffusion through the product layer was inferred as the rate-determining step. The order of the roasting process was found to be 2.158 and activation energy calculated to be 155.3 kJ/mol. Apart from potassium, sodium and excess calcium also got co-leached. To recover potassium from the leach liquor selectively, sodium perchlorate was added to precipitate potassium as KClO₄. Further, potassium perchlorate was thermally decomposed to give fertilizer grade potassium chloride (purity: 99.81%).

A Systematic Review on Analytical Methods to Determine Chiral and Achiral Forms of Venlafaxine and its Metabolite O-desmethylvenlafaxine

Background:

Venlafaxine (VEN) is a bicyclic phenylethylamine derivative and possesses a marked structural difference from other antidepressant drugs present in the market. It works by eliciting the neurotransmitter action in CNS. It occurs in two enantiomeric forms i.e. R and S VEN. After the first pass metabolism, it gets metabolized into more active form O-desmethylvenlafaxine (ODV) which also exist in the enantiomeric forms. So it is important to develop a suitable analytical and bioanalytical method for the determination of VEN and its metabolite to quantify them accurately.

Methods and Results:

The current review summarizes methods to determine chiral and achiral forms of VEN and ODV. According to the literature, it is clear that most widely used method for the determination of VEN and ODV is liquid chromatography-mass spectroscopy, other methods used for routine analysis include UV spectroscopy, reverse phase high-performance liquid chromatography with PDA detector. For the determination of enantiomeric forms of VEN and ODV, different chiral columns have been utilized. Capillary electrophoresis with charged cyclodextrins is also used to determine the enantiomeric forms.

Conclusion:

Various analytical methods for determining VEN and its metabolite in different matrices have been discussed thoroughly in the present review.

Digital conversations about suicide among teenagers and adults with epilepsy: A big-data, machine learning analysis

Objective

Digital media conversations can provide important insight into the concerns and struggles of people with epilepsy (PWE) outside of formal clinical settings and help generate useful information for treatment planning. Our study aimed to explore the big data from open‐source digital conversations among PWE with regard to suicidality, specifically comparing teenagers and adults, using machine learning technology.

Methods

Advanced machine‐learning empowered methodology was used to mine and structure open‐source digital conversations of self‐identifying teenagers and adults who endorsed suffering from epilepsy and engaged in conversation about suicide. The search was limited to 12 months and included only conversations originating from US internet protocol (IP) addresses. Natural language processing and text analytics were employed to develop a thematic analysis.

Results

A total of 222 000 unique conversations about epilepsy, including 9000 (4%) related to suicide, were posted during the study period. The suicide‐related conversations were posted by 7.8% of teenagers and 3.2% of adults in the study. Several critical differences were noted between teenagers and adults. A higher percentage of teenagers are: fearful of “the unknown” due to seizures (63% vs 12% adults), concerned about social consequences of seizures (30% vs 21%), and seek emotional support (29% vs 19%). In contrast, a significantly higher percentage of adults show a defeatist (“given up”) attitude compared to teenagers (42% vs 4%). There were important differences in the author's determined sentiments behind the conversations among teenagers and adults.

Significance

In this first of its kind big data analysis of nearly a quarter‐million digital conversations about epilepsy using machine learning, we found that teenagers engage in an online conversation about suicide more often than adults. There are some key differences in the attitudes and concerns, which may have implications for the treatment of younger patients with epilepsy.

Correction to: Pathologic Clavicle Fracture Secondary to Cutibacterium acnes Abscess: Case Report and Review of Literature

[This corrects the article DOI: 10.1007/s43465-020-00042-5.].

Smartphone Monitoring of Mood Instability in Young Depressed Patients: A Latent-class Analyses

This study captured daily and weekly mood ratings using a smartphone from bipolar disorder (BD) and unipolar major depression disorder (MDD) subjects at high (HRMDD) and low risk (LRMDD) for developing Bipolar Disorder (BD) and healthy controls (HC).

METHOD

40 subjects (18 - 30 yr) (6 BD, 13 HRMDD, 16 LRMDD and 5 HC) were studied and a total of 2401 daily and 744 weekly ratings were collected. HRMDD and LRMDD subjects were naturalistically treated with antidepressants. We investigate if latent-class analyses of ratings can detect mood instability among MDD and BD groups.

RESULTS

Our analyses revealed four underlying mood states correlating with clinical mood states. There was a trend for greater number of state changes in BD and HRMDD subjects compared to LRMDD and HC groups.

CONCLUSION

Smartphone ratings may adequately capture mood instability in BD subjects and at risk HRMDD subjects and offers a prudent way for monitoring development of serious manic symptoms.

Brain Changes Induced by Electroconvulsive Therapy Are Broadly Distributed

BACKGROUND

Electroconvulsive therapy (ECT) is associated with volumetric enlargements of corticolimbic brain regions. However, the pattern of whole-brain structural alterations following ECT remains unresolved. Here, we examined the longitudinal effects of ECT on global and local variations in gray matter, white matter, and ventricle volumes in patients with major depressive disorder as well as predictors of ECT-related clinical response.

METHODS

Longitudinal magnetic resonance imaging and clinical data from the Global ECT-MRI Research Collaboration (GEMRIC) were used to investigate changes in white matter, gray matter, and ventricle volumes before and after ECT in 328 patients experiencing a major depressive episode. In addition, 95 nondepressed control subjects were scanned twice. We performed a mega-analysis of single subject data from 14 independent GEMRIC sites.

RESULTS

Volumetric increases occurred in 79 of 84 gray matter regions of interest. In total, the cortical volume increased by mean ± SD of 1.04 ± 1.03% (Cohen's d = 1.01, p < .001) and the subcortical gray matter volume increased by 1.47 ± 1.05% (d = 1.40, p < .001) in patients. The subcortical gray matter increase was negatively associated with total ventricle volume (Spearman's rank correlation ρ = -.44, p < .001), while total white matter volume remained unchanged (d = -0.05, p = .41). The changes were modulated by number of ECTs and mode of electrode placements. However, the gray matter volumetric enlargements were not associated with clinical outcome.

CONCLUSIONS

The findings suggest that ECT induces gray matter volumetric increases that are broadly distributed. However, gross volumetric increases of specific anatomically defined regions may not serve as feasible biomarkers of clinical response.

Structural changes induced by electroconvulsive therapy are associated with clinical outcome

BACKGROUND

Electroconvulsive therapy (ECT) is the most effective treatment option for major depressive disorder, so understanding whether its clinical effect relates to structural brain changes is vital for current and future antidepressant research.

OBJECTIVE

To determine whether clinical response to ECT is related to structural volumetric changes in the brain as measured by structural magnetic resonance imaging (MRI) and, if so, which regions are related to this clinical effect. We also determine whether a similar model can be used to identify regions associated with electrode placement (unilateral versus bilateral ECT).

METHODS

Longitudinal MRI and clinical data (Hamilton Depression Rating Scale) was collected from 10 sites as part of the Global ECT-MRI research collaboration (GEMRIC). From 192 subjects, relative changes in 80 (sub)cortical areas were used as potential features for classifying treatment response. We used recursive feature elimination to extract relevant features, which were subsequently used to train a linear classifier. As a validation, the same was done for electrode placement. We report accuracy as well as the structural coefficients of regions included in the discriminative spatial patterns obtained.

RESULTS

A pattern of structural changes in cortical midline, striatal and lateral prefrontal areas discriminates responders from non-responders (75% accuracy, p < 0.001) while left-sided mediotemporal changes discriminate unilateral from bilateral electrode placement (81% accuracy, p < 0.001).

CONCLUSIONS

The identification of a multivariate discriminative pattern shows that structural change is relevant for clinical response to ECT, but this pattern does not include mediotemporal regions that have been the focus of electroconvulsive therapy research so far.

The NEO-FFI domain of openness to experience moderates ketamine response in treatment resistant depression

BACKGROUND

There are many putative mechanisms by which ketamine has its effect and many unanswered questions about risks and benefits of long-term ketamine therapy. A research imperative is the identification of predictors of response to intravenous ketamine, especially a sustained response to maintenance ketamine. Temperament is an inherited aspect of personality and is a predictive factor for outcome in treatment resistant depressed (TRD) patients.

METHODS

We analyzed which domains of personality impacted initial and sustained ketamine response. Utilizing the Neuroticism Extraversion Openness Five Factor Inventory (NEO-FFI) on 125 participants with TRD, we tested (1) whether the degree of neuroticism predicted initial and/or sustained response to ketamine; and (2) whether extraversion, agreeableness, openness to experience, and conscientiousness had an impact on response.

RESULTS

Our findings confirmed previous literature that elevated neuroticism, low conscientiousness, and low extraversion was the pattern of our TRD population regardless of response. Openness was the only factor to significantly predict sustained treatment outcome.

LIMITATIONS

Our findings are limited by the lack of placebo control, small sample size, non- standardized infusion intervals, polypharmacy rather than ketamine monotherapy, a select TRD population in that they had all failed ECT, and a primarily Caucasian population.

CONCLUSIONS

Our registry adds to the literature that factors making up temperament may have predictive value in regard to treatment response, specifically the outcome for TRD patients receiving long-term ketamine infusion therapy. If confirmed, assessing for Openness could reduce inappropriate exposure to ketamine with its attendant unknown long-term risks.

Heat Shock Factor 5 Is Essential for Spermatogenesis in Zebrafish

Heat shock factors (Hsfs) are transcription factors that regulate responses to heat shock and other environmental stimuli. Four heat shock factors (Hsf1-4) have been characterized from vertebrates to date. In addition to stress response, they also play important roles in development and gametogenesis. Here, we study the fifth member of heat shock factor family, Hsf5, using zebrafish as a model organism. Mutant hsf5^-/- males, generated by CRISPR/Cas9 technique, were infertile with drastically reduced sperm count, increased sperm head size, and abnormal tail architecture, whereas females remained fertile. We show that Hsf5 is required for progression through meiotic prophase 1 during spermatogenesis as suggested by the accumulation of cells in the leptotene and zygotene-pachytene stages and increased apoptosis in post-meiotic cells. hsf5^-/- mutants show gonadal misregulation of a substantial number of genes with roles in cell cycle, apoptosis, protein modifications, and signal transduction, indicating an important role of Hsf5 in early stages of spermatogenesis.

P1695Incidence and outcomes of unstable angina compared to non-ST elevation myocardial infarction

Objective

Assess the incidence and compare characteristics and outcome of unstable angina (UA) and Non-ST-Elevation myocardial infarction (NSTEMI)

Design

Two independent prospective multicenter diagnostic studies (Advantageous Predictors of Acute Coronary Syndromes Evaluation (APACE) and High-Sensitivity Troponin in the Evaluation of Patients With Acute Coronary Syndrome (High-STEACS)) enrolling patients with acute chest discomfort presenting to the emergency department. Central adjudication of the final diagnosis was done by two independent cardiologists using all clinical information including serial measurements of high-sensitivity cardiac troponin (hs-cTn). All-cause death and future non-fatal MI were assessed at 30-days and 1-year.

Results

8992 patients were enrolled at 11 centres. UA was adjudicated in 366/4122 (8.9%) and 137/4870 (2.8%) patients in APACE and High-STEACS, respectively, and NSTEMI in 622 (15.1%) and 651 (13.4%). Coronary artery disease was pre-existing in 73% and 76% of patients with unstable angina. At 30-days, all-cause mortality in UA was substantially lower as compared to NSTEMI (0.5% versus 3.7%, p=0.002 in APACE, 0.7% versus 7.4%, p=0.004 in High-STEACS). Similarly, at 1-year in UA all-cause mortality was 3.3% [95% CI 1.2–5.3] vs 10.4% [7.9–12.9] in APACE, and 5.1% [0.7–9.5] vs 22.9% [19.3–26.4] in High-STEACS, and similar to non-cardiac chest pain (NCCP). In contrast, future non-fatal MI in APACE was comparable in UA and NSTEMI (11.2%, [7.8–14.6] and 7.9%, [5.7–10.2]), and higher than in NCCP (0.6%, [0.2–1.0]).

1-year survival free from future AMI

Conclusions

The incidence and the mortality of UA is substantially lower than that of NSTEMI, while the rate of future non-fatal MI is similar.

Acknowledgement/Funding

Swiss National Science Foundation, Swiss Heart Foundation, Cardiovascular Research Foundation Basel, British Heart Foundation Project Grants, Butler S

Influence of physical activity on cardiac autonomic control in patients with dyslipidaemia

The objective of this study was to compare the cardiac autonomic control of dyslipidaemia patients engaged in different levels of physical activity and to determine the predictive ability of physical activity for cardiac autonomic dysfunction in these patients. This study also aimed to compare the cardiac autonomic control of dyslipidaemia patients and healthy adults. 52 patients (age: 49.1±4.53 years) with dyslipidaemia were recruited along with 16 healthy adults. Physical activity levels were assessed by International Physical Activity Questionnaire, and subjects were divided into three categories – low, moderate, and high physical activity. Heart rate variability (HRV) analysis was performed for obtaining time and frequency domain parameters. Presence of cardiac autonomic dysfunction was defined as standard deviation of N-N intervals <44 ms. HRV parameters were compared between 3 groups of dyslipidaemia patients and healthy controls. Predictive ability of physical activity for cardiac autonomic dysfunction in dyslipidaemia was evaluated after adjusting clinical covariates. There was a significant difference between low-frequency power (cardiac sympathetic control), and ratio of low- and high-frequency (HF) power (sympatho-vagal balance) in low versus moderate physical activity group and low versus high physical activity group (P<0.001). Significant differences were also observed for HFnu power (cardiac vagal activity) and total power between the dyslipidaemia groups. Physical activity was found to be a significant (P=0.03), independent predictor of cardiac autonomic dysfunction in dyslipidaemia patients. Findings of the present study suggest that cardiac autonomic profile of dyslipidaemia patients with different physical activity levels varied significantly. Dyslipidaemia patients engaged in moderate and high physical activity demonstrated significantly less sympathetic activity and better sympatho-vagal balance than those engaged in low levels of physical activity; also, vagal cardiac control was significantly greater in high physical activity group. Lower levels of physical activity determined the presence of cardiac autonomic dysfunction in these patients at an optimal cut-off value of ≤1,558 Metabolic Equivalent of Tasks- min/week.