The OP has tons of hyperlinks here's an article from the hyperlink, "inequality". As always, I strongly recommend reading from the original source:
ECONOMIC INEQUALITY AND HEALTH
By Peter Montague
It seems obvious that poor people are more likely to be sick, and to die at an earlier age, compared to rich people. Several recent studies from the U.S. confirm that this is the case.<1,2,3,4>
What is not so obvious is that the health of the poor is harmed in proportion to the size of the gap between rich and poor. It isn't the absolute level of poverty that matters so much as the size of the gap between rich and poor. In other words, "...what matters in determining mortality and health in a society is less the overall wealth of that society and more how evenly wealth is distributed. The more equally wealth is distributed the better the health of that society," according to an editorial in the BRITISH MEDICAL JOURNAL April 20th.<5> Two recent studies of the U.S. indicate that this is so,<6,7> and they are not the first to make the case.<8,9>
The two recent studies, published in April in the BRITISH MEDICAL JOURNAL, examine all 50 states within the U.S. Each study defines a measure of income inequality and compares it to various rates of disease and other social problems. Both the studies -- one from Harvard and one from University of California at Berkeley -- conclude that the greater the gap between rich and poor, the greater the chances that people will be sick and die young. It isn't the absolute level of wealth in a society that determines health; it is the size of the gap between rich and poor. Let's look at some of the details:
George Kaplan and his colleagues at Berkeley measured inequality in the 50 states as the percentage of total household income received by the less well off 50% of households.<6> It ranged from about 17% in Louisiana and Mississippi to about 23% in Utah and New Hampshire. In other words, by this measure, Utah and New Hampshire have the most EQUAL distribution of income, while Louisiana and Mississippi have the most UNEQUAL distribution of income.
This measure of income inequality was then compared to the age-adjusted death rate for all causes of death, and a pattern emerged: the more unequal the distribution of income, the greater the death rate. For example in Louisiana and Mississippi the age-adjusted death rate is about 960 per 100,000 people, while in New Hampshire it is about 780 per 100,000 and in Utah it is about 710 per 100,000 people. Adjusting these results for average income in each state did not change the picture: in other words, it is the gap between rich and poor, and not the average income in each state, that best predicts the death rate in each state.
This measure of income inequality was also tested against other social conditions besides health. States with greater inequality in the distribution of income also had higher rates of unemployment, higher rates of incarceration, a higher percentage of people receiving income assistance and food stamps, and a greater percentage of people without medical insurance. Again, the gap between rich and poor was the best predictor, not the average income in the state.
Interestingly, states with greater inequality of income distribution also spent less per person on education, had fewer books per person in the schools, and had poorer educational performance, including worse reading skills, worse math skills, and lower rates of completion of high school.
States with greater inequality of income also had a greater proportion of babies born with low birth weight; higher rates of homicide; higher rates of violent crime; a greater proportion of the population unable to work because of disabilities; a higher proportion of the population using tobacco; and a higher proportion of the population being sedentary (inactive).
Lastly, states with greater inequality of income had higher costs per-person for medical care, and higher costs per person for police protection.
More at link
http://www.huppi.com/kangaroo/Inequality&Health.htm