Circadian rhythm and circulating cell-free DNA release on healthy subjects.

In the last decade, clinical studies have investigated the clinical relevance of circulating cell-free-DNA (ccfDNA) as a diagnostic and prognosis tool in various diseases including cancers. However, limited knowledge on ccfDNA biology restrains its full development in the clinical practice. To improve our understanding, we evaluated the impact of the circadian rhythm on ccfDNA release in healthy subjects over a 24-h period. 10 healthy female subjects underwent blood sampling at 8am and 20 healthy male subjects underwent serial blood sampling (8:00 AM, 9:00 AM, 12:00 PM, 4:00 PM, 8:00 PM, 12:00 AM, 4 AM (+ 1 Day) and 8 AM (+ 1 Day)). We performed digital droplet-based PCR (ddPCR) assays to target 2 DNA fragments (69 & 243 bp) located in the KRAS gene to determine the ccfDNA concentration and fragmentation profile. As control, half of the samples were re-analyzed by capillary miniaturized electrophoresis (BIAbooster system). Overall, we did not detect any influence of the circadian rhythm on ccfDNA release. Instead, we observed a decrease in the ccfDNA concentration after meal ingestion, suggesting either a post-prandial effect or a technical detection bias due to a higher plasma load in lipids and triglycerides. We also noticed a potential effect of gender, weight and creatinine levels on ccfDNA concentration.

Similar Gut Hormone Secretions Two Years After One Anastomosis Gastric Bypass and Roux-en-Y Gastric Bypass: a Pilot Study.

OBJECTIVES: One-anastomosis gastric bypass (OAGB) is as effective as Roux-en-Y gastric bypass (RYGB) regarding weight loss and diabetes remission. However, there are no data on gut hormone secretions after OAGB. The aim of this study was to compare fasting and postprandial secretions of gut and pancreatic hormones in OAGB versus RYGB patients. DESIGN AND METHODS: Twenty-nine patients, 16 OAGB- and 13 RYGB-operated, underwent a liquid mixed-meal tolerance test at 2 years' post-surgery. Blood was sampled before and 15, 30, 60, 90, and 120 min after meal for plasma measurement of glucose, C-peptide, insulin, glucagon, GLP-1, GIP, GLP-2, PYY, and ghrelin. RESULTS: Percentage of total weight loss 2 years post-surgery were -33.9 ± 1.8% for OAGB and -31.2 ± 1.6% for RYGB (p = 0.6). Four patients with persistent diabetes were excluded for further analysis. Fasting and postprandial glucose levels (peaks and area under curve values) were similar between groups. HOMA index was lower in the OAGB group (0.8 ± 0.1 vs 1.3 ± 0.2 in RYGB, p < 0.05). Levels of C-peptide (or insulin) measured at 30 min were significantly lower in OAGB vs RYGB patients (6.9 ± 0.5 vs 9.7 ± 1.1 µg/l, p < 0.05). No difference was observed between OAGB and RYGB groups for GLP-1, GLP-2, PYY, or ghrelin postprandial secretions, but GIP tended to be lower in OAGB vs RYGB patients (756 ± 155 vs 1100 ± 188 pg/ml for postprandial peak concentrations, p = 0.06). CONCLUSIONS: This is the first clinical study showing that OAGB procedure, like RYGB, results in high postprandial secretions of gut hormones, in particular GLP-1. TRIAL REGISTRATION: Clinical Trials NCT03482895.

Adrenal adaptation in potassium-depleted men: role of progesterone?

BACKGROUND: In rodents, the stimulation of adrenal progesterone is necessary for renal adaptation under potassium depletion. Here, we sought to determine the role of progesterone in adrenal adaptation in potassium-depleted healthy human volunteers and compared our findings with data collected in patients with Gitelman syndrome (GS), a salt-losing tubulopathy. METHODS: Twelve healthy young men were given a potassium-depleted diet for 7 days at a tertiary referral medical centre (NCT02297048). We measured by liquid chromatography coupled to tandem mass spectroscopy plasma steroid concentrations at Days 0 and 7 before and 30 min after treatment with tetracosactide. We compared these data with data collected in 10 GS patients submitted to tetracosactide test. RESULTS: The potassium-depleted diet decreased plasma potassium in healthy subjects by 0.3 ± 0.1 mmol/L, decreased plasma aldosterone concentration by 50% (P = 0.0332) and increased plasma 17-hydroxypregnenolone concentration by 45% (P = 0.0232) without affecting other steroids. CYP17 activity, as assessed by 17-hydroxypregnenolone/pregnenolone ratio, increased by 60% (P = 0.0389). As compared with healthy subjects, GS patients had 3-fold higher plasma concentrations of aldosterone, 11-deoxycortisol (+30%) and delta 4-androstenedione (+14%). Their post-tetracosactide progesterone concentration was 2-fold higher than that of healthy subjects and better correlated to plasma potassium than to plasma renin. CONCLUSION: The increase in 17-hydroxypregnenolone concentration after mild potassium depletion in otherwise healthy human subjects suggests that 17 hydroxylation of pregnenolone prevents the increase in progesterone observed in potassium-depleted mice. The unexpected over-response of non-mineralocorticoid steroids to tetracosactide in GS subjects suggests that the adrenal system not only adapts to sodium depletion but may also respond to hypokalaemia.