Intermittent fasting for systemic triglyceride metabolic reprogramming (IFAST): Design and methods of a prospective, randomized, controlled trial.

BACKGROUND: Caloric restriction prolongs lifespan in model organisms and improves metrics of aging-related diseases in humans, but daily compliance is challenging. Intermittent fasting improves metrics of lipid and glucose metabolism in the setting of weight loss but whether these metrics are improved independent of weight loss is not known. METHODS: We seek to address this gap with IFAST, a single-center, three-arm, prospective, randomized, controlled clinical trial. Eligible study participants are adults with no chronic medical conditions beyond prediabetes or overweight but who are at high risk for type 2 diabetes mellitus (T2D), defined as having a history of gestational diabetes or a first-degree relative with T2D. Participants will be randomized in a 1:2:2 schema to either a control group, a fasting group, or a fasting/weight maintenance group. The fasting groups will complete a 24-h fast one day per week for 12 weeks. The key mechanistic endpoint is change in triglyceride composition (defined by carbon content and degree of saturation) as measured by longitudinal metabolomics. The key safety endpoint is percent change from baseline in bone volume fraction (BV/TV; high-resolution peripheral quantitative CT) at the radius in the fasting group. Secondary endpoints include measures of insulin sensitivity (hyperinsulinemic-euglycemic clamp), clinical lipid profiling, systemic inflammation markers, hunger assessment, bone density, and bone microarchitecture with high-resolution peripheral quantitative CT. CONCLUSION: IFAST will investigate intrinsic metabolic benefits of intermittent fasting beyond weight loss. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT05722873.

Methionine as a regulator of bone remodeling with fasting.

Caloric restriction improves metabolic health but is often complicated by bone loss. We studied bone parameters in humans during a 10-day fast and identified candidate metabolic regulators of bone turnover. Pro-collagen 1 intact N-terminal pro-peptide (P1NP), a bone formation marker, decreased within 3 days of fasting. Whereas dual-energy x-ray absorptiometry measures of bone mineral density were unchanged after 10 days of fasting, high-resolution peripheral quantitative CT demonstrated remodeling of bone microarchitecture. Pathway analysis of longitudinal metabolomics data identified one-carbon metabolism as fasting dependent. In cultured osteoblasts, we tested the functional significance of one-carbon metabolites modulated by fasting, finding that methionine - which surged after 3 days of fasting - affected markers of osteoblast cell state in a concentration-dependent manner, in some instances exhibiting a U-shaped response with both low and high concentrations driving putative antibone responses. Administration of methionine to mice for 5 days recapitulated some fasting effects on bone, including a reduction in serum P1NP. In conclusion, a 10-day fast in humans led to remodeling of bone microarchitecture, potentially mediated by a surge in circulating methionine. These data support an emerging model that points to a window of optimal methionine exposure for bone health.

Evidence for ~12-h ultradian gene programs in humans.

Mice and many marine organisms exhibit ~12-h ultradian rhythms, however, direct evidence of ~12-h ultradian rhythms in humans is lacking. Here, we performed prospective, temporal transcriptome profiling of peripheral white blood cells from three healthy humans. All three participants independently exhibited robust ~12-h transcriptional rhythms in molecular programs involved in RNA and protein metabolism, with strong homology to circatidal gene programs previously identified in Cnidarian marine species.

The Effect of Zoledronic Acid on Bone Microarchitecture and Strength after Denosumab and Teriparatide Administration: DATA-HD Study Extension.

The combination of denosumab and teriparatide is an effective treatment strategy in postmenopausal osteoporosis, though skeletal gains are promptly lost when these agents are discontinued. In the DATA-HD study, we reported that a single dose of zoledronic acid (ZOL) maintains the increases in areal spine and hip bone mineral density (BMD) achieved with this combination for at least 12 months. The capacity of ZOL to maintain corresponding improvements in peripheral volumetric BMD and microarchitecture, however, has not been reported. In the 15-month DATA-HD study, 76 postmenopausal osteoporotic women were randomized to receive 9 months of teriparatide (20-µg or 40-µg daily) overlapped with denosumab (60 mg at months 3 and 9). In the Extension study, 53 participants received a single dose of ZOL (5 mg intravenously) 24-35 weeks after the last denosumab dose. We measured volumetric BMD and microarchitecture at the distal radius and tibia using high-resolution peripheral quantitative computed tomography at months 27 and 42. Despite ZOL administration, total and cortical BMD gradually decreased over 27 months resulting in values similar to baseline at the radius but still significantly above baseline at the tibia. At both sites, cortical porosity decreased to values below pretreatment baseline at month 27 but then increased from month 27 to 42. There were no significant changes in trabecular parameters throughout the 27-month post-ZOL observation period. Stiffness and failure load, at both sites, decreased progressively from month 15 42 though remained above baseline at the tibia. These findings suggest that in contrast to the largely maintained gains in dual-energy X-ray absorptiometry (DXA)-derived spine and hip BMD, a single dose of ZOL was not as effective in maintaining the gains in volumetric peripheral bone density and microarchitecture produced by 15 months of overlapping treatment with denosumab and teriparatide. Alternative therapeutic approaches that can fully maintain improvements in peripheral bone parameters require further study. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Evidence for conservation of primordial ~12-hour ultradian gene programs in humans under free-living conditions.

While circadian rhythms are entrained to the once daily light-dark cycle of the sun, many marine organisms exhibit ~12h ultradian rhythms corresponding to the twice daily movement of the tides. Although human ancestors emerged from circatidal environment millions of years ago, direct evidence of ~12h ultradian rhythms in humans is lacking. Here, we performed prospective, temporal transcriptome profiling of peripheral white blood cells and identified robust ~12h transcriptional rhythms from three healthy participants. Pathway analysis implicated ~12h rhythms in RNA and protein metabolism, with strong homology to the circatidal gene programs previously identified in Cnidarian marine species. We further observed ~12h rhythms of intron retention events of genes involved in MHC class I antigen presentation, synchronized to expression of mRNA splicing genes in all three participants. Gene regulatory network inference revealed XBP1, and GABP and KLF transcription factor family members as potential transcriptional regulators of human ~12h rhythms. These results suggest that human ~12h biological rhythms have a primordial evolutionary origin with important implications for human health and disease.

Effects of Combination Denosumab and High-Dose Teriparatide Administration on Bone Microarchitecture and Estimated Strength: The DATA-HD HR-pQCT Study.

In postmenopausal women at high risk of fracture, we previously reported that combined denosumab and high-dose (HD; 40 µg) teriparatide increased spine and hip bone mineral density (BMD) more than combination with standard-dose teriparatide (SD; 20 µg). To assess the effects of these combinations on bone microarchitecture and estimated bone strength, we performed high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia in these women, who were randomized to receive either teriparatide 20 µg (n = 39) or 40 µg (n = 37) during months 0 to 9 overlapped with denosumab 60 mg s.c. given at months 3 and 9, for a 15-month study duration. The 69 women who completed at least one study visit after baseline are included in this analysis. Over 15 months, increases in total BMD were higher in the HD-group than the SD-group at the distal tibia (5.3% versus 3.4%, p = 0.01) with a similar trend at the distal radius (2.6% versus 1.0%, p = 0.06). At 15 months, cortical porosity remained similar to baseline, with absolute differences of -0.1% and -0.7% at the distal tibia and -0.4% and -0.1% at the distal radius in the HD-group and SD-group, respectively; p = NS for all comparisons. Tibial cortical tissue mineral density increased similarly in both treatment groups (1.3% [p < 0.0001 versus baseline] and 1.5% [p < 0.0001 versus baseline] in the HD-group and SD-group, respectively; p = 0.75 for overall group difference). Improvements in trabecular microarchitecture at the distal tibia and estimated strength by micro-finite element analysis at both sites were numerically greater in the HD-group compared with SD-group but not significantly so. Together, these findings suggest that short-term treatment combining denosumab with either high- or standard-dose teriparatide improves HR-pQCT measures of bone density, microstructure, and estimated strength, with greater gains in total bone density observed in the HD-group, which may be of benefit in postmenopausal women with severe osteoporosis. © 2020 American Society for Bone and Mineral Research (ASBMR).

Efficacy of Zoledronic Acid in Maintaining Areal and Volumetric Bone Density After Combined Denosumab and Teriparatide Administration: DATA-HD Study Extension.

Combined teriparatide and denosumab rapidly and substantially increases bone mineral density (BMD) at all anatomic sites. Discontinuation of denosumab however, results in high-turnover bone loss and increased fracture risk. The optimal way to prevent this bone loss remains undefined. This study is a preplanned extension of the DATA-HD study, where postmenopausal women with osteoporosis were randomized to receive 9 months of either 20 µg or 40 µg of teriparatide daily overlapping with denosumab (60 mg administered at months 3 and 9). At the completion of this 15-month study, women were invited to enroll in the DATA-HD Extension where they received a single dose of zoledronic acid (5 mg) 24 to 35 weeks after the last denosumab dose. Areal BMD and bone turnover markers were measured at month 27 and 42 (12 and 27 months after zoledronic acid, respectively) and spine and hip volumetric bone density by quantitative CT was measured at month 42. Fifty-three women enrolled in the DATA-HD Extension. At the femoral neck and total hip, the mean 5.6% and 5.1% gains in BMD achieved from month 0 to 15 were maintained both 12 and 27 months after zoledronic acid administration. At the spine, the mean 13.6% gain in BMD achieved from month 0 to 15 was maintained for the first 12 months but modestly decreased thereafter, resulting in a 3.0% reduction (95% CI, -4.0% to -2.0%, p < .0001) 27 months after zoledronic acid. The pattern of BMD changes between months 15 and 42 were qualitatively similar in the 20-µg and 40-µg groups. A single dose of zoledronic acid effectively maintains the large and rapid total hip and femoral neck BMD increases achieved with combination teriparatide/denosumab therapy for at least 27 months following the transition. Spine BMD was also largely, though not fully, maintained during this period. These data suggest that the DATA-HD Extension regimen may be an effective strategy in the long-term management of patients at high risk of fragility fracture. © 2021 American Society for Bone and Mineral Research (ASBMR).

Bone Mineral Density Response With Denosumab in Combination With Standard or High-Dose Teriparatide: The DATA-HD RCT.

CONTEXT: In the Denosumab and High-Dose Teriparatide Administration (DATA-HD) study, we reported that 15 months of combined high-dose (HD) teriparatide and denosumab increased mean areal bone mineral density (aBMD) at the hip and spine more than combined denosumab and standard-dose (SD) teriparatide. OBJECTIVE: In the current analysis, we compare the individual rates of aBMD response between the treatment groups. DESIGN: Single-site, open-label, randomized controlled trial in which postmenopausal women received either teriparatide 20-µg daily (SD) or 40-µg daily (HD) given months 0 through 9, overlapped with denosumab 60 mg, given months 3 through 15 (15 months' total duration). The proportion of participants in the SD and HD groups experiencing total hip, femoral neck, and lumbar spine aBMD gains of >3%, >6%, and >9% were compared. PARTICIPANTS: Postmenopausal women with osteoporosis completing all study visits (n = 60). MAIN OUTCOME MEASURE(S): aBMD (dual x-ray absorptiometry). RESULTS: At the end of the 15-month treatment period, a higher proportion of women in the HD group had aBMD increases >3% (83% vs. 58%, P = .037) and >6% (45% vs. 19%, P = .034) at the total hip, and >3% at the femoral neck (86% vs. 63%, P = .044). At the lumbar spine, >3% response rates were similar, whereas the >6% and >9% response rates were greater in the HD group (100% vs. 79%, P = .012 and 93% vs. 59%, P = .003, respectively). CONCLUSION: Compared with the SD regimen, more women treated with the HD regimen achieved clinically meaningful and rapid gains in hip and spine aBMD. These results suggest that this approach may provide unique benefits in the treatment of postmenopausal osteoporosis.

Combination denosumab and high dose teriparatide for postmenopausal osteoporosis (DATA-HD): a randomised, controlled phase 4 trial.

BACKGROUND: In the Denosumab and Teriparatide Administration (DATA) study, we showed that denosumab fully inhibits teriparatide-induced bone resorption while allowing for continued teriparatide-induced bone formation, resulting in larger increases in hip and spine bone mineral density (BMD) than with either drug alone. We aimed to assess whether administration of denosumab with high dose teriparatide would stimulate larger increases in bone mass than those observed in the DATA study. METHODS: DATA-HD was an open-label, randomised, controlled phase 4 trial done at Massachusetts General Hospital. Eligible women were postmenopausal women (at least 36 months since last menses or since hysterectomy with a follicle-stimulating hormone concentration of ≥40 U/L) with osteoporosis. Participants were randomly assigned (1:1) to receive teriparatide 20 µg (standard dose) or 40 µg (high dose) daily via subcutaneous injection for 9 months. At 3 months, both groups were started on denosumab 60 mg every 6 months via subcutaneous injection for 12 months. Areal BMD (aBMD) was measured at 0, 3, 9, and 15 months. Treatment was given open label, but outcome assessors were masked. The primary endpoint was percentage change from baseline in spine areal BMD (aBMD) at 15 months. Women who completed at least one study visit after baseline were included in the modified intention-to-treat analysis. Safety was assessed in all randomly assigned participants. This study is registered with ClinicalTrials.gov, number NCT02176382. FINDINGS: Between Oct 15, 2014, and June 10, 2016, 269 women were assessed for eligibility. 76 participants were randomly assigned to 20 µg teriparatide (n=39) or 40 µg teriparatide (n=37), of whom 69 completed at least one post-baseline visit. At 15 months, mean spine aBMD had increased to a significantly greater extent in the 40 µg group (17·5% [SD 6·0] increase) than the 20 µg group (9·5% [3·2]; difference 8·1%, 95% CI 5·5 to 10·6, p<0·0001). Mean femoral neck aBMD had also increased to a greater extent in the 40 µg group (6·8% [SD 4·1] increase) than the 20 µg group (4·3% [3·7]; difference 2·5%, 0·5 to 4·5, p=0·04), as did mean total hip aBMD (40 µg group, 6·1% [3·4] increase; 20 µg group, 3·9% [2·9] increase; difference 2·2%, 0·6 to 3·8, p<0·0001). 30 (77%) of 39 participants in the 20 µg group and 29 (78%) of 37 participants in the 40 µg group had an adverse event, and seven (18%) and two (5%) patients had serious adverse events. The most frequent adverse events were joint pain (15 [38%]), muscle cramp (15 [38%]), and fatigue (12 [31%]) in the 20 µg group group and fatigue (14 [38%]), nausea (16 [43%]), and joint pain (17 [46%]) in the 40 µg group. No deaths were reported. INTERPRETATION: Combined treatment with teriparatide 40 µg and denosumab increases spine and hip BMD more than standard combination therapy. This large and rapid increase in bone mass suggest that this high dose regimen might provide a method of restoring skeletal integrity in patients with osteoporosis. FUNDING: National Institutes of Health and the Dart Foundation.