Bernard Surial

Introduction: Global awareness to chemsex, a specific form of sexualized psychoactive substance (“chems”) use among gay, bisexual and other men who have sex with men (gbMSM), is increasing. We aimed to assess prevalence, patterns and implications of “chems” use on chemsex‐related outcomes. Methods: We conducted a Swiss‐wide longitudinal study using individual‐level data from April 2019 to December 2024 of adult gbMSM with HIV, enrolled in the Swiss HIV Cohort Study (SHCS), or taking HIV pre‐exposure prophylaxis (PrEP), enrolled in SwissPrEPared. Determinants of “chems” (methamphetamine, new psychoactive stimulants, GHB/GBL) use and clinical implications were analysed using logistic regression. Longitudinal “chems” use patterns were distinguished by rule‐based classification. Point‐prevalences of “chems” use, including COVID‐19 and mpox periods, were analysed using interrupted time series analysis. Results: We analysed 107,855 follow‐up visits from 13,304 gbMSM. “Chems” were used by 17.2% of gbMSM (21.4% in SwissPrEPared vs. 11.2% in the SHCS). Age below 26 (compared to 26−37, adjusted odds ratio [aOR]: 0.82, 95%‐confidence interval: 0.68−0.96), over 37 (aOR for 38−48: 0.84, 0.75−0.94; aOR for over 48: 0.54, 0.47−0.62) and bisexual orientation showed lower odds (aOR: 0.78, 0.66−0.90), while participation in French‐speaking SwissPrEPared centres (aOR compared to SHCS Eastern Switzerland: 1.41, 1.22−1.64) and sex with non‐steady partners showed higher odds for “chems” use (aOR: 12.44, 8.85−18.17). “Chems” use was associated with depression, inconsistent condom use, high non‐steady partner count and sexually transmitted infections (STIs). Comparing longitudinal use patterns, temporally restricted use, that is, recovering from stable use, reported “chems” use only once, or for a single episode shorter than 1 year, showed the lowest risk for STIs and high partner count, whereas intermittent use showed lower risk only for syphilis. “Chems” use decreased marginally during COVID‐19 and mpox, with a quick return and no difference to levels before COVID‐19. Conclusions: A large proportion of gbMSM use “chems,” with congruent determinants across both cohorts but heterogeneous impact on sexual and mental health that varies by specific substance and longitudinal use patterns. Further understanding of underlying mechanisms driving this heterogeneity is needed before delivering mechanism‐informed interventions tailored to “chems” use patterns, like STI and depression screening, harm‐reduction counselling and linkage to addiction care.

Background: Integrase strand transfer inhibitors (INSTIs) are highly effective components of antiretroviral therapy for HIV. Recent studies suggest increased cardiovascular disease (CVD) risk after INSTI initiation, but findings remain inconsistent. The Swiss HIV Cohort Study is nationally representative, collects high-quality data, and provides an ideal setting for independent evaluation using causal methods, avoiding participant overlap in multicountry HIV-cohort consortiums. Methods: We emulated sequential target trials from November 2011 to September 2025 to estimate the effect of switching from non-INSTI to INSTI-based treatment on 6-year CVD risk among treatment-experienced people with HIV. Eligible participants were ≥18 years old, INSTI-naive, virally suppressed, and without CVD history. For each trial, participants were assigned to remain on non-INSTI or switch to INSTI. Intention-to-treat (ITT) and per-protocol (PP) effects were estimated using pooled logistic regression with baseline adjustment (ITT) and inverse probability weighting (PP). Results: Among 8815 individuals contributing 539 017 person-trials, 5750 switched to INSTI, and 507 CVD events occurred. In ITT analyses, the adjusted risk ratio for switching versus remaining on non-INSTI was 1.34 (95% confidence interval 1.03–1.69) after 1 year, and 1.03 (0.88–1.16) after 6 years. Absolute risk differences were small, ranging from 0.20 percentage points (0.02–0.37) after 1 year to 0.13 (-0.49 to 0.58) after 6 years. Per-protocol estimates were similar. Conclusions: Switching to INSTI-based treatment did not substantially increase long-term CVD risk in treatment-experienced individuals with well-controlled HIV. The early increase in absolute risk was small and was not expected to be clinically meaningful. This further contextualizes results from multicountry analyses.

Background: A previous RESPOND analysis suggested that integrase inhibitors (INSTIs) increase cardiovascular disease (CVD) risk compared with other antiretroviral therapy (ART). We reanalyzed the data using target trial emulations examining the impact of methodological choices. Methods: Treatment-naïve analyses included ART-naïve adults with detectable HIV viraemia and recent CD4 and HIV-RNA measurements. Treatment-experienced analyses included adults with suppressed HIV-RNA receiving INSTI-free ART. We estimated adjusted risk differences (RDs) and risk ratios (RRs) for CVD events comparing INSTI initiation or switching versus other ART using inverse-probability weighting and pooled logistic regression. Results: Among 7111 treatment-naïve individuals, 95 CVD events occurred over a median of 62 months. Risk ratios comparing INSTI initiation with starting other ART were 1.07 (95% confidence interval .29–4.93) at 1 year, 1.21 (.41–3.91) at 2 years, and 1.87 (1.06–3.26) at 6 years. Corresponding RDs were 0.02% (−.32–.29), 0.09% (−.43–.53), and 1.03% (0.08–2.07). Among 22 921 treatment-experienced individuals, 800 CVD events occurred over a median of 37 months. Risk ratios were 1.55 (1.16–2.00) at 1 year, 1.30 (1.07–1.62) at 2 years, and 0.93 (.78–1.09) at 6 years. Corresponding RDs were 0.26% (.08–.47), 0.29% (.03–.58), and −0.22 (−.66–.25). Conclusions: Switching to INSTIs was associated with a transient increase in CVD risk during the first 2 years among treatment-experienced individuals, whereas starting INSTIs in ART-naïve individuals was associated with a gradual increase over time, albeit based on few events. Absolute RDs remained small, but the findings suggest a potential impact of INSTIs on the development of CVD.

Introduction: Tobacco smoking is an insufficiently addressed health burden among people living with HIV. The Reduce tobacco use in people living with HIV in Switzerland (RETUNE) trial tests the effectiveness of offering a menu of nicotine substitute products, including e-cigarettes, nicotine...

Introduction: Injectable long‐acting antiretroviral therapy (iLA‐ART) offers a valuable alternative to oral ART (oART). While the efficacy of these treatment strategies is similar, adequate information on their specific characteristics is essential to enable people with HIV (PWH) to decide which option best suits their values and preferences. Methods: We conducted a multicentric survey of PWH on oART in the Swiss HIV Cohort Study (SHCS). Using a questionnaire co‐developed with expert patients, we assessed participants' (1) values and preferences on characteristics of modern oART and treatment satisfaction, (2) knowledge about iLA‐ART with cabotegravir/rilpivirine, (3) reasons influencing their interest to switch or not to iLA‐ART and (4) perceived burden of treatment (BOT) taking oART. Outcomes were rated on an 11‐point (0–10) Likert scale. We explored outcomes' determinants using multivariate analyses. Results: A total of 200 PWH on oART participated (response rate 87%), with a median age of 52 years (Interquartile Range 45–59), 58 (29%) were women, and 90 (45%) were men who have sex with men. Treatment satisfaction was very high (mean 9.3, Standard Deviation [SD] 1.3) and perceived BOT on oART was low (mean 2.5, SD 2.0). The two most valued oART characteristics were effectiveness (mean 9.9, SD 0.3) and absence of side effects (mean 9.5, SD 1.7). Overall, 76 (39%) participants had never heard about iLA‐ART, with large differences between the 3 participating centres (60% vs. 3% vs. 50%). In multivariable analysis, women (Odds Ratio 0.35, 95% confidence interval [CI] 0.14–0.85) and PWH ≥60 years (0.27, 0.08–0.94) were less aware about iLA‐ART. Reasons influencing PWH's potential interest to switch to iLA‐ART varied individually, while the main reason for preferring to stay on oART was the bimonthly dosing interval of iLA‐ART. Conclusion: In Switzerland, over one‐third of PWH were unaware of iLA‐ART despite its reimbursed availability. The provider of care appears to be the main driver of these findings, while women and older individuals showed the lowest awareness. As ART characteristics are valued individually, providing systematic information on available treatment options and engaging PWH in shared decision‐making could help address identified disparities and empower them to choose the treatment that best aligns with their preferences.

Background: Among people living with HIV, there has been a shift of focus from HIV-related health issues to cardiovascular diseases and cancer. For both, tobacco smoking is a major but insufficiently addressed etiological factor. Evidence from randomized trials suggests that nicotine substitute products such as e-cigarettes and nicotine patches can reduce tobacco smoking and its associated health burden. However, most previous smoking cessation trials primarily included people who are motivated to quit smoking and focused on testing a single nicotine substitute product. The effectiveness of offering a menu of nicotine substitute products to tobacco smokers regardless of their willingness to quit smoking (“opt-out” approach) is unknown. Methods: Reduce tobacco use in people living with HIV in Switzerland (RETUNE, NCT06789692) is a pragmatic, 1:1 randomized, multicenter, superiority clinical trial using the Trials within Cohorts (TwiCs) design within the Swiss HIV Cohort Study. RETUNE assesses the effectiveness of offering a menu of different nicotine substitute products, namely electronic cigarettes, nicotine pouches, and nicotine patches, versus usual care. Cohort participants are eligible if they smoke more than one tobacco cigarette per day, do not use any of the substitute products, and have signed the randomization consent following the TwiCs design. Participants randomized to the intervention may choose any of the offered substitutes to be used free of charge for 6 months or decline the offer. Overall, we plan to recruit 972 participants. The primary outcome is tobacco abstinence at 6 months measured as participant-reported past 7-day prevalence abstinence. The primary outcome will be assessed in the intention-to-treat set using a logistic regression model adjusted for region, men having sex with men, current drug users, and number of cigarettes per day at baseline. Secondary outcomes are long-term smoking cessation rates and tobacco-associated health outcomes. Discussion: RETUNE started recruitment in February 2025 and is currently ongoing. RETUNE using the TwiCs design will clarify the effectiveness of a preference-based opt-out smoking cessation intervention among people living with HIV. Trial registration: Clinicaltrials.gov NCT06789692. Registered on January 17th, 2025. The manuscript is aligned with the registry. https://clinicaltrials.gov/study/NCT06789692?cond=NCT06789692&rank=1

Background: To inform hepatocellular carcinoma (HCC) surveillance after hepatitis C virus (HCV) cure with direct-acting antivirals (DAA), we estimated HCC risk post-DAA in people with human immunodeficiency virus (HIV) with advanced liver fibrosis or cirrhosis under universal DAA. Methods: We used data from HepCAUSAL, a collaboration of cohorts of HIV–HCV coinfection from Europe and North America. Eligibility criteria were HIV–HCV coinfection, advanced liver fibrosis or cirrhosis, DAA naïve, HIV-RNA < 50 copies/mL, on antiretroviral therapy, no HBV coinfection, and no prior HCC diagnosis or liver transplant. Follow-up started when eligibility was met and ended at HCC diagnosis, death, loss to follow-up, 6 years, or database closure, whichever came first. We estimated the 6-year risk and annual probability of HCC if all eligible individuals had initiated DAA at baseline using a weighted pooled logistic model for the monthly HCC risk among DAA initiators. Results: Of 3824 eligible individuals (92% males, median age 60 years [IQR: 54, 64]), 2373 (62%) who initiated DAA, 43 had an HCC diagnosis during follow-up. The estimated 6-year HCC risk (95% CI) under universal DAA was 2.5% (1.6, 3.9). Annual HCC probability was 0.81% (0.34, 1.54) between baseline and month 12 after DAA initiation, 0.64% (0.28, 1.19) between years 1 and 2, 0.50% (0.27, 0.84) between years 2 and 3, 0.34% (0.13, 0.63) between years 3 and 4, 0.19% (0.07, 0.33) between years 4 and 5, and 0.10% (0.01, 0.24) between years 5 and 6. Conclusions: An estimated 2.5% of people with HIV and advanced liver fibrosis or cirrhosis are diagnosed with HCC by 6 years post-DAA. Annual probability of HCC declines over time and falls below 0.4% after 3 years.

Background: Type 2 diabetes (T2D) is among the most frequent comorbidities in people with HIV (PWH) and occurs more often in PWH than in people without HIV. Polygenic risk scores (PRS) can be used to summarize the genetic risk for T2D, but it is unknown to what extent HIV-specific factors affect on or interact with genetic risk factors. Methods: We performed a case control study using incidence density sampling to match participants with T2D to controls within the Swiss HIV Cohort Study (mean age 51.9; 73.8% male). Conditional logistic regression was used to evaluate risk factors for T2D, including two PRSs (for T2D and BMI), adjusting for age, sex, ethnicity, BMI, waist–hip ratio, antiretroviral treatment regimen, and CD4-cell count. Prediction accuracy was assessed by leave-one-out cross-validation and computing the area under the receiver operator characteristic curve. Results: Analyzing 687 cases and 2441 controls, we found a clear dose–response relationship between the PRSs for T2D and T2D, with participants in the highest PRS-quintile having an over three times larger risk of T2D [odds ratio, OR (95% CI: 3.41 [2.61 to 5.11)] compared with the first quintile. CD4-cell count at T2D diagnosis was not associated with T2D [1.01 (0.94 to 1.09)]. Compared with an non-nucleoside reverse transcriptase inhibitor–based antiretroviral treatment regimen, an INSTI-based regimen was associated with an increased T2D risk [2.45 (1.68 to 3.58)], as was a PI-based regimen [1.70 (1.22 to 2.37)]. Conclusions: We found that CD4-cell counts are not associated with the risk of T2D, and that neither CD4-cell count nor cumulative exposure to non-nucleoside reverse transcriptase inhibitor or INSTI-class antiretrovirals modify this risk.