How is Testosterone related with Cardiometabolic Risks?

Certain risk factors have been shown to cluster with clinical conditions like obesity, type 2 diabetes and cardiovascular problems. Such clustering of risk factors have led investigators to propose a new condition called cardiometabolic risk syndrome. Cardiometabolic risk has gained much attention recently and has been linked directly with visceral adiposity. Few investigations have implicated a direct link between centrally obese men and low levels of testosterone. Association of Testosterone with insulin resistance, obesity, diabetes and atheroschlerosis has been presented earlier but has not received much attention. Higher incidence of metabolic syndrome has also been hypothesized to be associated with decline in testosterone levels. There is evidence that testosterone replacement therapy results in reduced insulin resistance and central obesity in type 2 diabetic men. In this study, we have investigated relationship between testosterone and markers of cardiometabolic risk.

A cohort of male patient samples from ZRT database was selected for the study and categorized in tertiles based on testosterone levels with low (<300),>800). The relationship between testosterone levels and cardiometabolic risk was evaluated using bloodspot testing of insulin, hemoglobin A1c, triglycerides and high sensitivity c-reactive protein. All bloodspot assays were developed in house and showed good correlations with serum/plasma levels of risk markers tested.

A total of 124 male patient samples (41 with testosterone levels <>800 ng/dL) were tested for cardiometabolic risk markers. Mean age (+/- SD) was 50.8 (+/- 12.8). Insulin (4.7 µIU/mL) and high sensitivity c-reactive protein (1.83 mg/L) were found to be significantly lower in the highest tertile with testosterone levels greater than 800 ng/dL when compared with insulin (6.3 µIU/mL) and hs-CRP (3.46 mg/L) concentrations in the lowest tertile with testosterone levels less than 300 ng/dL. There was no significant difference observed in HbA1c and triglyceride levels in different groups.

Our data suggest that a higher testosterone level in men is associated with lower CRP and insulin concentrations. These patients may have a lower risk of developing metabolic syndrome and/or atheroschlerotic cardiovascular events.

Dried Blood Spot Screening for Cardiometabolic Risk Markers shows Benefits of Exercise

The prevalence of diabetes and cardiovascular disease is increasing at an alarming rate. Several clinical and observational studies have demonstrated reduced risk of diabetes when physical activity increases. Simple screening tools are needed to monitor effects of treatment interventions in individuals at high risk.

At ZRT Laboratory in Beaverton, Oregon we assessed the application of dried blood spot technology to measure important cardiometabolic risk markers. Dried blood spot collection has advantages compared to conventional blood draws, such as minimal invasiveness, low sample volume, convenience of repeated measurements and ease of sample storage and transport.

Fifteen participants (28- 63 years of age) enrolled in a fitness study that included 30 minute exercise/ brisk walking five days a week for four months. Levels of insulin, hemoglobin A1c, C-reactive protein and triglycerides were measured in blood spot samples obtained by a simple and easy finger stick before and after the program. Dried blood spot samples were stored at -20C until used for analysis using modified methods developed in house from commercially available assays.

Insulin levels decreased significantly ; triglycerides dropped by 18% and C-reactive protein levels also showed significant improvement. The HbA1c levels remained unchanged during the program.

In conclusion, exercise/ brisk walking for 30 minutes five days a week for four months improved cardiometabolic risk factors independently as confirmed by dried bloodspot testing. This simple screening method has important implications for monitoring overall cardiometabolic health of high risk individuals.

Which is more important- C Reactive Protein or Cholesterol?

I wish to open this discussion to get feedback from all those clinicians and researchers out there struggling to find out which one is a better predictor of overall risk of cardiovascular events. Many of us and in fact most of us have been focussed on the cholesterol levels to determine the risk until a recently published study (JUPITER Study) in New England Journal of Medicine reported that C Reactive Protein (CRP) may be a better predictor and an independent marker of cardiovascular risk as opposed to just LDL cholesterol. The study showed that patients with high LDL cholesterol and high CRP levels were at higher risk than those with high LDL cholesterol but low CRP levels. It was also observed that patients with normal LDL cholesterol with high CRP levels are at higher risk than those with normal LDL cholesterol and low or normal CRP levels. In these patients, measuring only the LDL cholesterol may not be very helpful or in other words, these patients may not be identified as those at risk and may end up developing a coronary artery disease.

We know that CRP is released in response to any inflammation in the body. Several studies have shown a connection between inflammation and atherosclerosis, which is basically attested by the JUPITER study.

Does that mean that we should start measuring CRP levels regularly to screen or monitor patients at high risk? Is it still important to measure LDL cholesterol? Do we really need to know the triglyceride levels? Should we still look at other risk markers now that we have CRP as an emerging independent marker?

I personally feel that body does not work in isolation and relying upon just one or two risk factors may not be a smart decision. It is extremely important to consider the overall balance of major physiological functions within the body to get a comprehensive picture of overall risk.