Effects of Vitamin D Supplementation on Telomere Length: An Analysis of Data from the Randomised Controlled D-Health Trial.

OBJECTIVES: Observational studies have suggested that a higher 25-hydroxyvitamin D concentration may be associated with longer telomere length; however, this has not been investigated in randomised controlled trials. We conducted an ancillary study within a randomised, double-blind, placebo-controlled trial of monthly vitamin D (the D-Health Trial) for the prevention of all-cause mortality, conducted from 2014 to 2020, to assess the effect of vitamin D supplementation on telomere length (measured as the telomere to single copy gene (T/S) ratio). DESIGN, SETTING, PARTICIPANTS, AND INTERVENTION: Participants were Australians aged 60-84 years and we randomly selected 1,519 D-Health participants (vitamin D: n=744; placebo: n=775) for this analysis. We used quantitative polymerase chain reaction to measure the relative telomere length (T/S ratio) at 4 or 5 years after randomisation. We compared the mean T/S ratio between the vitamin D and placebo groups to assess the effect of vitamin D supplementation on relative telomere length, using a linear regression model with adjustment for age, sex, and state which were used to stratify the randomisation. RESULTS: The mean T/S ratio was 0.70 for both groups (standard deviation 0.18 and 0.16 for the vitamin D and placebo groups respectively). The adjusted mean difference (vitamin D minus placebo) was -0.001 (95% CI -0.02 to 0.02). There was no effect modification by age, sex, body mass index, or predicted baseline 25-hydroxyvitamin D concentration. CONCLUSION: In conclusion, routinely supplementing older adults, who are largely vitamin D replete, with monthly doses of vitamin D is unlikely to influence telomere length.

An alternative method of wound pain control following hepatic resection: a preliminary study.

BACKGROUND: Epidural analgesia is considered one of the optimal methods for provision of postoperative pain relief in patients recovering from major upper abdominal operations. Concerns regarding the potential risk of neurological complications prompted an evaluation of an alternative strategy using a continuous intermuscular bupivacaine (CIB) infusion combined with patient-controlled analgesia (PCA). METHODS: Two fine-bore catheters are inserted in the deep intermuscular intercostal neuronal plane during abdominal wound closure, and a continuous infusion of bupivacaine 0.25% is commenced for 72 h postoperatively. Simultaneously, patient-controlled analgesia provided intravenous morphine on demand. The study comprised 10 consecutive patients undergoing liver resection in whom CIB infusion and PCA were employed. The feasibility, safety and efficacy of the technique were investigated, analysing postoperative pain scores, morphine requirements, spirometry and oxygen saturation. RESULTS: There were no postoperative deaths. Postoperative morbidity included one urinary tract infection, one minor chest infection and acute confusional episodes in two patients. Median pain scores and morphine requirements at 12, 24, 48 and 72 h postoperatively were satisfactory. Spirometry and oxygen saturation values also remained within the normal range. DISCUSSION: Preliminary experience with CIB infusion/PCA in the aftermath of major liver resection has demonstrated its simplicity and safety as an alternative method of postoperative pain control. Further study is required to investigate the role of CIB infusion/PCA as a practical alternative to epidural analgesia or PCA alone.

Effectiveness of Ford's belt reminder system in increasing seat belt use.

OBJECTIVES: The study investigated the effectiveness in increasing seat belt use of Ford's belt reminder system, a supplementary system that provides intermittent flashing lights and chimes for five minutes if drivers are not belted. METHODS: Seat belt use of drivers in relatively new cars with and without the reminder system was unobtrusively observed as vehicles were brought to dealerships for service. RESULTS: Overall use rates were estimated at 71% for drivers in vehicles without the reminder system and 76% for drivers in vehicles with belt reminders (p<0.01). CONCLUSIONS: Seat belt use is relatively low in the United States. The present study showed that vehicle based reminder systems can be at least modestly effective in increasing belt use, which may encourage further development of such systems.

Bovine pericardial patch angioplasty in carotid endarterectomy.

Patch angioplasty during carotid endarterectomy (CEA) has been shown to reduce the incidence of both early and late complications. Controversy continues, however, over the ideal patch material. Bovine pericardium (Vascu-Guard Biovascular Inc., Saint Paul, MN) offers an attractive alternative to other patch materials because of its handling and suturing characteristics that are similar to that of autogenous material. This study examines the perioperative and midterm results of bovine pericardial patch angioplasty during CEA. We studied 112 patients who underwent 129 CEAs with bovine pericardial patch angioplasty during an 18-month period. Data were collected regarding demographics, operative indications, perioperative complications, and the occurrence of late adverse outcomes based primarily on follow-up arterial duplex studies. Among this group there were 63 male (56%) and 49 female (44%) patients whose mean age was 71.8 +/- 9.1 years. In these patients there was the typical distribution of atherosclerotic risk factors. Seventy-four patients (66%) had symptomatic disease preoperatively and the remaining 38 patients (34%) were asymptomatic. Temporary cranial nerve palsy occurred in three patients (2%). There were no perioperative strokes, acute occlusions, bleeding episodes requiring reoperation, or deaths. The patients were followed up to 54 months postoperatively with a mean follow-up time of 41.7 +/- 4.4 months. During this period two patients (2%) developed three significant restenoses (70-99%). All required reoperation. There were no asymptomatic occlusions, infections, aneurysms, or rupture. These data demonstrate that bovine pericardial patch angioplasty during CEA is associated with a low incidence of both perioperative and midterm adverse outcomes.

Child seating position and restraint use in three states.

OBJECTIVE: Because of risks from deploying airbags to children in front seats, extensive publicity has been aimed at getting them restrained and in rear seats. The objective of this study was to assess restraint use and seating positions among children in vehicles with and without airbags. METHOD: Surveys were conducted in cities in Michigan, North Carolina, and Texas 1998. Restraint use and seating position were noted for all children, as well as their estimated age, driver belt use, airbag presence, and vehicle license plate number. RESULTS: Fewer children were observed in the front seats of vehicles with passenger airbags (24%) than in vehicles without them (36%). Most of the children seated in front were ages 7-12 (44%-61%), followed by 3-6 year olds (29%-35%). Very few children ages 0-2 were seated in front (5%-12%). The overwhelming majority of children ages 0-2 were restrained. However, children ages 3-6 seated in the front were least likely to be restrained and most likely to be improperly restrained. Restraint use was higher when the driver was belted, but about 30% of 3-6 year olds were unrestrained even with a belted driver. CONCLUSIONS: Efforts should continue to educate parents about the importance of correct restraint use and rear seating for children, particularly once children move from child safety seats into adult belts. Efforts also should be made to enforce the seat belt laws that exist in every state.

Relationship of head restraint positioning to driver neck injury in rear-end crashes.

Insurance claims were examined for evidence of neck injuries to drivers of passenger cars struck in the rear. Neck injury rates were significantly lower for male drivers, elderly drivers, and drivers in less severe crashes. Even after accounting for differences in driver demographics and crash severity, neck injury rates were significantly lower for drivers of cars with head restraints that were more likely to be behind the heads of motorists.

Venous morbidity after superficial femoral-popliteal vein harvest.

PURPOSE: The superficial femoral-popliteal vein (SFPV) is a reliable conduit for aortoiliac, infrainguinal, and venous reconstructions. In this prospective study, we characterized the anatomic and physiologic changes in SFPV harvest limbs and their relationship to the development of late venous complications. METHODS: Since 1990, we have studied 61 patients after harvest of 86 SFPVs at 6-month intervals with clinical examinations, lower-extremity venous duplex, and venous function tests. The CEAP system was used as a means of categorizing clinical changes. RESULTS: Mean (+/- SEM) follow-up was 37 +/- 3 months. Less than one third of harvest limbs had edema without skin changes (C3). No patient had major chronic venous changes (C4 to C6) or venous claudication. There were no significant differences in limb measurements between harvest and non-harvest limbs, except in a subgroup of patients with unilateral harvest in which there was a small but significant (P =.046) increase in harvest limb thigh and calf circumference, compared with the opposite non-harvest limb. These clinical results were not affected by the presence or absence of an intact greater saphenous vein (GSV). Large, direct collaterals (4 to 6 mm in diameter) between the popliteal vein stump and profunda femoris vein (PFV) were seen by means of duplex ultrasonography in 29 harvest limbs (34%). The remainder appeared to have smaller, less direct collaterals to the PFV. Mild venous reflux with rapid cuff deflation was present at the popliteal or posterior tibial vein in nine of 79 harvest limbs (11%). Six of these nine limbs (67%) with reflux were clinical class C3, compared with only 19 of the 70 limbs without reflux (27%; P =.02). Ambulatory venous pressure (AVP) with exercise was significantly increased in harvest limbs (60 +/- 4.7 mm Hg), compared with non-harvest limbs (47.8 +/- 5.2 mm Hg; P =.049). The AVP recovery time of harvest limbs (14.0 +/- 1.0 seconds) was reduced, compared with non-harvest limbs (23.5 +/- 4.5 seconds; P =.02). AVPs (exercise) remained stable or decreased in six of 10 harvest limbs measured serially. Venous refill time in harvest limbs (15.1 +/- 1.1 seconds) was shortened, compared with non-harvest limbs (22.3 +/- 2. 1 seconds)(P =.002). Venous outflow obstruction measured by means of plethysmography was present in 93% of harvest limbs, compared with 36% of non-harvest limbs (P =.001). CONCLUSION: SFPV harvest results in minimal mid-term to late-term lower-extremity venous morbidity despite outflow obstruction. The most likely mechanisms preserving clinical status include the low incidence of mild reflux, the presence of collateral venous channels, and the lack of progression in abnormal harvest limb physiology. The absence of the ipsilateral GSV does not adversely affect clinical outcome.

Drinking drivers missed at sobriety checkpoints.

OBJECTIVE: Sobriety checkpoints are an effective deterrent to alcohol-impaired driving although a substantial proportion of drinking drivers who pass through checkpoints are missed. The present study was designed to determine the extent to which police officers correctly identify individuals with blood alcohol concentrations (BACs) at or above 0.05% at checkpoints, and if there are characteristics of drivers, vehicles or checkpoints that are associated with decreased chances of detection. METHOD: To determine which drivers are likely to be missed, drivers not detained by police for additional sobriety evaluation were interviewed and voluntary breath samples were provided at 156 sobriety checkpoints in North Carolina. RESULTS: More than 50% of the drivers with BACs in excess of 0.08% and almost 90% of drivers with BACs in excess of 0.05% were not detained by officers. For drivers with BACs of 0.05% or higher, women and those 35 or younger were more likely to be missed than were men and older drivers. Drivers without passengers were more likely to be missed than those with passengers. Drivers were also more likely to be missed during weekend checkpoints. Similar results were found for drivers with BACs at or above 0.08%. CONCLUSIONS: Alerting police officers to characteristics of drinking drivers more likely to be missed may improve detection rates. In addition, passive alcohol sensors could improve the effectiveness and efficiency of sobriety checkpoints in detecting drinking drivers.

The use of feedback signs to increase observed daytime seat belt use in two cities in North Carolina.

Well publicized enforcement programs in North Carolina have raised seat belt use to about 80%. In an effort to find techniques to raise belt use further, signs providing feedback to drivers on belt use rates were introduced in two communities, Asheboro (population 18,000) and Greensboro (population 183,000). Feedback signs remind motorists about belt use and imply a constant and vigorous enforcement presence. The signs were prominently posted by the roadside at high volume locations; belt use information was changed weekly based on observational surveys. Observed daytime driver belt use in Asheboro increased from an average of 75% before the signs to 89% after the signs were established. At urban sites in Greensboro, driver belt use increased from 80% to 86%. Right front passenger belt use increased significantly in Asheboro but not in Greensboro. There were no changes in belt use at two interstate exit sites in Greensboro. Reasons for the differential success rates may relate to differences in initial belt use rates, community size, amount of publicity, and numbers of encounters with the signs. It is clear, however, that feedback signs can be an important supplement to belt use enforcement programs.

Driver experience with antilock brake systems.

Antilock brakes provide the capability for shorter stopping distances and the ability to steer and maintain control during hard braking, especially on wet and slippery surfaces. Owners of late model cars equipped with antilock brakes were surveyed in North Carolina and Wisconsin regarding their experiences with antilocks. The survey results indicated that more than 50% of the drivers in North Carolina and 40% in Wisconsin incorrectly indicated how to brake a car in an emergency situations on wet and slippery pavements in a way that will effectively activate the antilock feature. More drivers in Wisconsin than in North Carolina reported that their cars' antilock feature had been used, but more than 33% of the Wisconsin drivers and 62% of North Carolina drivers said they had never used the antilock feature of their cars' brakes.

Use of seatbelts in cars with automatic belts.

Use of seatbelts in late model cars with automatic or manual belt systems was observed in suburban Washington, DC, Chicago, Los Angeles, and Philadelphia. In cars with automatic two-point belt systems, the use of shoulder belts by drivers was substantially higher than in the same model cars with manual three-point belts. This finding was true in varying degrees whatever the type of automatic belt, including cars with detachable nonmotorized belts, cars with detachable motorized belts, and especially cars with nondetachable motorized belts. Most of these automatic shoulder belts systems include manual lap belts. Use of lap belts was lower in cars with automatic two-point belt systems than in the same model cars with manual three-point belts; precisely how much lower could not be reliably estimated in this survey. Use of shoulder and lap belts was slightly higher in General Motors cars with detachable automatic three-point belts compared with the same model cars with manual three-point belts; in Hondas there was no difference in the rates of use of manual three-point belts and the rates of use of automatic three-point belts.

Seat belt use in cars with air bags.

Seat belt use was observed in 1,628 cars with air bags and manual belts and 34,223 cars with manual seat belts only. Sixty-six percent of drivers in cars with air bags wore seat belts compared to 63 percent of drivers in cars with manual belts only. The study found no evidence for the speculation that drivers with air bags will reduce their seat belt use because they believe an air bag alone provides sufficient protection.

Seat belt use on interstate highways.

More than 5,000 miles of limited-access highways in the eastern United States and Canada were traveled to observe seat belt use. Overall belt use was 58 percent in the United States and 79 percent in Canada. The data indicate that belt use in the United States follows a different pattern on interstate highways than on other streets and roads, with relatively high belt use rates (over 50 percent) appearing to be somewhat independent of belt use law provisions.

Observed use of automatic seat belts in 1987 cars.

Usage of the automatic belt systems supplied by six large-volume automobile manufacturers to meet the federal requirements for automatic restraints were observed in suburban Washington, D.C., Chicago, Los Angeles, and Philadelphia. The different belt systems studied were: Ford and Toyota (motorized, nondetachable automatic shoulder belt), Nissan (motorized, detachable shoulder belt), VW and Chrysler (nonmotorized, detachable shoulder belt), and GM (nonmotorized detachable lap and shoulder belt). Use of automatic belts was significantly greater than manual belt use in otherwise comparable late-model cars for all manufacturers except Chrysler; in Chrysler cars, automatic belt use was significantly lower than manual belt use. The automatic shoulder belts provided by Ford, Nissan, Toyota, and VW increased use rates to about 90%. Because use rates were lower in Ford cars with manual belts, their increase was greater. GM cars had the smallest increase in use rates; however, lap belt use was highest in GM cars. The other manufacturers supply knee bolsters to supplement shoulder belt protection; all--except VW--also provide manual lap belts, which were used by about half of those who used the automatic shoulder belt. The results indicate that some manufacturers have been more successful than others in providing automatic belt systems that result in high use that, in turn, will mean fewer deaths and injuries in those cars.

The mortality consequences of raising the speed limit to 65 mph on rural interstates.

As of April 1987, states were permitted to raise the speed limit on rural interstates to 65 mph without incurring federal sanctions; 38 states elected to do so in 1987. Fatality data for the months when the new limit was in effect in 1987 were compared with fatalities in the same months of 1982-86 on rural interstates and other rural roads. Fatalities on rural interstates in the states with increased speed limits in 1987 were conservatively estimated to be 15 percent higher than they would have been if the states had retained the 55 mph limit (95% CI = 6, 24). Among states that retained the 55 mph limit, fatalities on rural interstates were 6 percent lower than expected (95% CI = -23, 13).

Coverage gaps in seat belt use laws.

Some seat belt use laws exempt occupants in certain seating positions and in certain types of vehicles, or both. A state-by-state analysis was conducted of the extent to which passenger vehicle occupants killed before the laws went into effect would have been covered by the laws subsequently passed. Only five states had laws that covered all passenger vehicle occupants; the majority excluded 4 to 8 per cent and six states excluded 14 per cent or more. More inclusive laws can reduce injuries and save lives.

Shoulder belt use in four states with belt use laws.

Shoulder belt use was observed before and after belt use laws went into effect in New York, New Jersey, Illinois, and Texas. There were large increases in belt use rates in each state in the first month the laws were enforced. In the three states in which post-law observations were made more than once, belt use declined from the levels seen in the first month; rates generally dropped to less than 50 percent. This pattern of decline from initial use rates has also been found in other jurisdictions around the world. Combined enforcement and publicity campaigns have been shown to be capable of reversing this trend and to increase use rates to 65 percent or more. Such campaigns will be needed to maximize the effect of seat belt use laws in the United States.

Child restraint laws: an analysis of gaps in coverage.

The limiting effects of exemptions to the coverage of child restraint laws were estimated by determining the extent to which the laws would have applied to child motor vehicle occupants, ages 0-5 years, killed before the laws were passed (1976-80). The 50 state laws would have exempted about 39 per cent of child motor vehicle occupants less than 6 years of age killed in the years immediately preceding enactment of the laws. Of those children killed in pre-law years who were within the age limits set by the subsequent state laws, about 21 per cent would not have been covered. The gaps in the laws are unnecessary, and proper amendments based on these data can save lives.