The baseline characteristics of 303 enrolled PLWH at the time of switching regimens are detailed in Table 1.

HIV-RNA levels were measured at different follow-up visits. Sustained virological suppression was achieved in 96.7% (58/60), 97.5% (78/80), 95.9% (71/74) and 100% (85/85) of patients at 3, 6, 9, and 12 months after switching to DTG/3TC, respectively. Among those patients who did not achieve virological suppression, HIV-RNA were detected at low levels, 123 copies/mL and 496 copies/mL at month 3, 56 copies/mL and 67 copies/mL at month 6, and 284 copies/mL, 72 copies/mL and 96 copies/mL at month 9.

There were no significant changes in CD4 counts following the regimen switch, with a median change of 42 cells/μL (IQR, −63 to 91 cells/μL, p = 0.582) at month 6 and 44 cells/μL at month 12 (IQR, −47 to106 cells/μL, p = 0.575), respectively.

We compared the changes in serum lipid levels from baseline to 12 months after regimen switch in 239 patients with available data. The serum levels of total cholesterol (TC) (p = 0.289), triglycerides (TG) (p = 0.373), and high-density lipoprotein cholesterol (HDL-C) (p = 0.305) did not change significantly. However, a significant elevation of low-density lipoprotein cholesterol (LDL-C) (p < 0.001) was observed. See Fig. 1.

Changes in serum lipid profiles. Comparison of serum lipid levels before and 12 months after switching to dolutegravir/lamivudine (DTG/3TC) (a). Comparison of changes in serum lipid profiles between individuals prior on tenofovir (TDF)-based and non-TDF-based regimens (b), as well as those previously exposed to efavirenz (EFV) and DTG regimens (c). TC total cholesterol, TG triglycerides, HDL-C high-density lipoprotein cholesterol, LDL-C low-density lipoprotein cholesterol

Subgroup analyses were further performed based on prior ART regimens, comparing the TDF-based group (n = 131) with the non-TDF-based group (n = 108), as well as the DTG-based group (n = 88) with the EFV-based group (n = 104). Changes in serum levels of TC (p < 0.001), TG (p < 0.001) and HDL-C (p = 0.001) exhibited significant disparities between the non-TDF-based and TDF-based regimens, with a decrease in the former and an increase in the latter, respectively. ​LDL-C levels were similarly elevated in both TDF-based and non-TDF-based groups (p = 0.711). There were no significant differences in the changes of TC (p = 0.370), HDL-C (p = 0.313) and LDL-C (p = 0.247) levels between the DTG-based and the EFV-based groups. However, the DTG-based group exhibited an increase while the EFV-based group showed a decrease in TG levels following switch to DTG/3TC (p = 0.032). See Fig. 1.

The changes in serum levels of kidney and bone metabolic markers from baseline to month 12 following the switch were evaluated in 245 participants with available data. Serum creatinine levels increased from 80.9 μmol/L (IQR: 67.7–90.8) to 87.7 μmol/L (IQR:77.09–96.5) (p < 0.001). The estimated glomerular filtration rate (eGFR, mL/min*1.73m2) decreased from 97.8 (IQR:84.30–117.60) to 89.1 (IQR:77.40–101.10) (p < 0.001). No significant changes were observed in the serum levels of cystatin C (0.70 mg/L vs. 0.68 mg/L, p = 0.239). Alkaline phosphatase (ALP), a bone metabolic marker, showed a significant decrease from 89 U/L (IQR:74–106) to 72 U/L (IQR: 61–89) (p < 0.001). Subgroup analyses were conducted based on previous ART regimens, comparing the TDF-based group (n = 133) with the non-TDF-based group (n = 112). ALP exhibited a more pronounced decrease in the TDF-based group compared to the non-TDF based group (−20 U/L vs. −12.5 U/L, p < 0.001).